diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2017-11-16 13:06:27 -0800 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2017-11-16 13:06:27 -0800 |
commit | 051089a2eed9a9977080774f3793ff2688cd3878 (patch) | |
tree | 29e23a60ea7e98633a3eef8dd436b57d7d41986d /drivers | |
parent | 974aa5630b318938273d7efe7a2cf031c7b927db (diff) | |
parent | 646d944c2ef5a3b298c4e150494c71b9272d8b47 (diff) | |
download | linux-rt-051089a2eed9a9977080774f3793ff2688cd3878.tar.gz |
Merge tag 'for-linus-4.15-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip
Pull xen updates from Juergen Gross:
"Xen features and fixes for v4.15-rc1
Apart from several small fixes it contains the following features:
- a series by Joao Martins to add vdso support of the pv clock
interface
- a series by Juergen Gross to add support for Xen pv guests to be
able to run on 5 level paging hosts
- a series by Stefano Stabellini adding the Xen pvcalls frontend
driver using a paravirtualized socket interface"
* tag 'for-linus-4.15-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: (34 commits)
xen/pvcalls: fix potential endless loop in pvcalls-front.c
xen/pvcalls: Add MODULE_LICENSE()
MAINTAINERS: xen, kvm: track pvclock-abi.h changes
x86/xen/time: setup vcpu 0 time info page
x86/xen/time: set pvclock flags on xen_time_init()
x86/pvclock: add setter for pvclock_pvti_cpu0_va
ptp_kvm: probe for kvm guest availability
xen/privcmd: remove unused variable pageidx
xen: select grant interface version
xen: update arch/x86/include/asm/xen/cpuid.h
xen: add grant interface version dependent constants to gnttab_ops
xen: limit grant v2 interface to the v1 functionality
xen: re-introduce support for grant v2 interface
xen: support priv-mapping in an HVM tools domain
xen/pvcalls: remove redundant check for irq >= 0
xen/pvcalls: fix unsigned less than zero error check
xen/time: Return -ENODEV from xen_get_wallclock()
xen/pvcalls-front: mark expected switch fall-through
xen: xenbus_probe_frontend: mark expected switch fall-throughs
xen/time: do not decrease steal time after live migration on xen
...
Diffstat (limited to 'drivers')
-rw-r--r-- | drivers/ptp/ptp_kvm.c | 5 | ||||
-rw-r--r-- | drivers/xen/Kconfig | 11 | ||||
-rw-r--r-- | drivers/xen/Makefile | 1 | ||||
-rw-r--r-- | drivers/xen/grant-table.c | 244 | ||||
-rw-r--r-- | drivers/xen/manage.c | 7 | ||||
-rw-r--r-- | drivers/xen/privcmd.c | 3 | ||||
-rw-r--r-- | drivers/xen/pvcalls-back.c | 4 | ||||
-rw-r--r-- | drivers/xen/pvcalls-front.c | 1278 | ||||
-rw-r--r-- | drivers/xen/pvcalls-front.h | 28 | ||||
-rw-r--r-- | drivers/xen/time.c | 72 | ||||
-rw-r--r-- | drivers/xen/xenbus/xenbus_probe_frontend.c | 2 |
11 files changed, 1619 insertions, 36 deletions
diff --git a/drivers/ptp/ptp_kvm.c b/drivers/ptp/ptp_kvm.c index 2b1b212c219e..c67dd11e08b1 100644 --- a/drivers/ptp/ptp_kvm.c +++ b/drivers/ptp/ptp_kvm.c @@ -178,8 +178,11 @@ static int __init ptp_kvm_init(void) { long ret; + if (!kvm_para_available()) + return -ENODEV; + clock_pair_gpa = slow_virt_to_phys(&clock_pair); - hv_clock = pvclock_pvti_cpu0_va(); + hv_clock = pvclock_get_pvti_cpu0_va(); if (!hv_clock) return -ENODEV; diff --git a/drivers/xen/Kconfig b/drivers/xen/Kconfig index 4545561954ee..d8dd54678ab7 100644 --- a/drivers/xen/Kconfig +++ b/drivers/xen/Kconfig @@ -196,6 +196,17 @@ config XEN_PCIDEV_BACKEND If in doubt, say m. +config XEN_PVCALLS_FRONTEND + tristate "XEN PV Calls frontend driver" + depends on INET && XEN + default n + select XEN_XENBUS_FRONTEND + help + Experimental frontend for the Xen PV Calls protocol + (https://xenbits.xen.org/docs/unstable/misc/pvcalls.html). It + sends a small set of POSIX calls to the backend, which + implements them. + config XEN_PVCALLS_BACKEND bool "XEN PV Calls backend driver" depends on INET && XEN && XEN_BACKEND diff --git a/drivers/xen/Makefile b/drivers/xen/Makefile index d3930ecaf11d..451e833f5931 100644 --- a/drivers/xen/Makefile +++ b/drivers/xen/Makefile @@ -37,6 +37,7 @@ obj-$(CONFIG_XEN_EFI) += efi.o obj-$(CONFIG_XEN_SCSI_BACKEND) += xen-scsiback.o obj-$(CONFIG_XEN_AUTO_XLATE) += xlate_mmu.o obj-$(CONFIG_XEN_PVCALLS_BACKEND) += pvcalls-back.o +obj-$(CONFIG_XEN_PVCALLS_FRONTEND) += pvcalls-front.o xen-evtchn-y := evtchn.o xen-gntdev-y := gntdev.o xen-gntalloc-y := gntalloc.o diff --git a/drivers/xen/grant-table.c b/drivers/xen/grant-table.c index a8721d718186..139e018a82b0 100644 --- a/drivers/xen/grant-table.c +++ b/drivers/xen/grant-table.c @@ -33,6 +33,7 @@ #define pr_fmt(fmt) "xen:" KBUILD_MODNAME ": " fmt +#include <linux/bootmem.h> #include <linux/sched.h> #include <linux/mm.h> #include <linux/slab.h> @@ -43,6 +44,7 @@ #include <linux/hardirq.h> #include <linux/workqueue.h> #include <linux/ratelimit.h> +#include <linux/moduleparam.h> #include <xen/xen.h> #include <xen/interface/xen.h> @@ -52,6 +54,9 @@ #include <xen/hvc-console.h> #include <xen/swiotlb-xen.h> #include <xen/balloon.h> +#ifdef CONFIG_X86 +#include <asm/xen/cpuid.h> +#endif #include <asm/xen/hypercall.h> #include <asm/xen/interface.h> @@ -68,15 +73,26 @@ static int gnttab_free_count; static grant_ref_t gnttab_free_head; static DEFINE_SPINLOCK(gnttab_list_lock); struct grant_frames xen_auto_xlat_grant_frames; +static unsigned int xen_gnttab_version; +module_param_named(version, xen_gnttab_version, uint, 0); static union { struct grant_entry_v1 *v1; + union grant_entry_v2 *v2; void *addr; } gnttab_shared; /*This is a structure of function pointers for grant table*/ struct gnttab_ops { /* + * Version of the grant interface. + */ + unsigned int version; + /* + * Grant refs per grant frame. + */ + unsigned int grefs_per_grant_frame; + /* * Mapping a list of frames for storing grant entries. Frames parameter * is used to store grant table address when grant table being setup, * nr_gframes is the number of frames to map grant table. Returning @@ -130,14 +146,15 @@ struct unmap_refs_callback_data { static const struct gnttab_ops *gnttab_interface; -static int grant_table_version; -static int grefs_per_grant_frame; +/* This reflects status of grant entries, so act as a global value. */ +static grant_status_t *grstatus; static struct gnttab_free_callback *gnttab_free_callback_list; static int gnttab_expand(unsigned int req_entries); #define RPP (PAGE_SIZE / sizeof(grant_ref_t)) +#define SPP (PAGE_SIZE / sizeof(grant_status_t)) static inline grant_ref_t *__gnttab_entry(grant_ref_t entry) { @@ -210,7 +227,7 @@ static void put_free_entry(grant_ref_t ref) } /* - * Following applies to gnttab_update_entry_v1. + * Following applies to gnttab_update_entry_v1 and gnttab_update_entry_v2. * Introducing a valid entry into the grant table: * 1. Write ent->domid. * 2. Write ent->frame: @@ -229,6 +246,15 @@ static void gnttab_update_entry_v1(grant_ref_t ref, domid_t domid, gnttab_shared.v1[ref].flags = flags; } +static void gnttab_update_entry_v2(grant_ref_t ref, domid_t domid, + unsigned long frame, unsigned int flags) +{ + gnttab_shared.v2[ref].hdr.domid = domid; + gnttab_shared.v2[ref].full_page.frame = frame; + wmb(); /* Hypervisor concurrent accesses. */ + gnttab_shared.v2[ref].hdr.flags = GTF_permit_access | flags; +} + /* * Public grant-issuing interface functions */ @@ -260,6 +286,11 @@ static int gnttab_query_foreign_access_v1(grant_ref_t ref) return gnttab_shared.v1[ref].flags & (GTF_reading|GTF_writing); } +static int gnttab_query_foreign_access_v2(grant_ref_t ref) +{ + return grstatus[ref] & (GTF_reading|GTF_writing); +} + int gnttab_query_foreign_access(grant_ref_t ref) { return gnttab_interface->query_foreign_access(ref); @@ -282,6 +313,29 @@ static int gnttab_end_foreign_access_ref_v1(grant_ref_t ref, int readonly) return 1; } +static int gnttab_end_foreign_access_ref_v2(grant_ref_t ref, int readonly) +{ + gnttab_shared.v2[ref].hdr.flags = 0; + mb(); /* Concurrent access by hypervisor. */ + if (grstatus[ref] & (GTF_reading|GTF_writing)) { + return 0; + } else { + /* + * The read of grstatus needs to have acquire semantics. + * On x86, reads already have that, and we just need to + * protect against compiler reorderings. + * On other architectures we may need a full barrier. + */ +#ifdef CONFIG_X86 + barrier(); +#else + mb(); +#endif + } + + return 1; +} + static inline int _gnttab_end_foreign_access_ref(grant_ref_t ref, int readonly) { return gnttab_interface->end_foreign_access_ref(ref, readonly); @@ -442,6 +496,37 @@ static unsigned long gnttab_end_foreign_transfer_ref_v1(grant_ref_t ref) return frame; } +static unsigned long gnttab_end_foreign_transfer_ref_v2(grant_ref_t ref) +{ + unsigned long frame; + u16 flags; + u16 *pflags; + + pflags = &gnttab_shared.v2[ref].hdr.flags; + + /* + * If a transfer is not even yet started, try to reclaim the grant + * reference and return failure (== 0). + */ + while (!((flags = *pflags) & GTF_transfer_committed)) { + if (sync_cmpxchg(pflags, flags, 0) == flags) + return 0; + cpu_relax(); + } + + /* If a transfer is in progress then wait until it is completed. */ + while (!(flags & GTF_transfer_completed)) { + flags = *pflags; + cpu_relax(); + } + + rmb(); /* Read the frame number /after/ reading completion status. */ + frame = gnttab_shared.v2[ref].full_page.frame; + BUG_ON(frame == 0); + + return frame; +} + unsigned long gnttab_end_foreign_transfer_ref(grant_ref_t ref) { return gnttab_interface->end_foreign_transfer_ref(ref); @@ -563,19 +648,26 @@ void gnttab_cancel_free_callback(struct gnttab_free_callback *callback) } EXPORT_SYMBOL_GPL(gnttab_cancel_free_callback); +static unsigned int gnttab_frames(unsigned int frames, unsigned int align) +{ + return (frames * gnttab_interface->grefs_per_grant_frame + align - 1) / + align; +} + static int grow_gnttab_list(unsigned int more_frames) { unsigned int new_nr_grant_frames, extra_entries, i; unsigned int nr_glist_frames, new_nr_glist_frames; + unsigned int grefs_per_frame; - BUG_ON(grefs_per_grant_frame == 0); + BUG_ON(gnttab_interface == NULL); + grefs_per_frame = gnttab_interface->grefs_per_grant_frame; new_nr_grant_frames = nr_grant_frames + more_frames; - extra_entries = more_frames * grefs_per_grant_frame; + extra_entries = more_frames * grefs_per_frame; - nr_glist_frames = (nr_grant_frames * grefs_per_grant_frame + RPP - 1) / RPP; - new_nr_glist_frames = - (new_nr_grant_frames * grefs_per_grant_frame + RPP - 1) / RPP; + nr_glist_frames = gnttab_frames(nr_grant_frames, RPP); + new_nr_glist_frames = gnttab_frames(new_nr_grant_frames, RPP); for (i = nr_glist_frames; i < new_nr_glist_frames; i++) { gnttab_list[i] = (grant_ref_t *)__get_free_page(GFP_ATOMIC); if (!gnttab_list[i]) @@ -583,12 +675,12 @@ static int grow_gnttab_list(unsigned int more_frames) } - for (i = grefs_per_grant_frame * nr_grant_frames; - i < grefs_per_grant_frame * new_nr_grant_frames - 1; i++) + for (i = grefs_per_frame * nr_grant_frames; + i < grefs_per_frame * new_nr_grant_frames - 1; i++) gnttab_entry(i) = i + 1; gnttab_entry(i) = gnttab_free_head; - gnttab_free_head = grefs_per_grant_frame * nr_grant_frames; + gnttab_free_head = grefs_per_frame * nr_grant_frames; gnttab_free_count += extra_entries; nr_grant_frames = new_nr_grant_frames; @@ -938,6 +1030,12 @@ int gnttab_unmap_refs_sync(struct gntab_unmap_queue_data *item) } EXPORT_SYMBOL_GPL(gnttab_unmap_refs_sync); +static unsigned int nr_status_frames(unsigned int nr_grant_frames) +{ + BUG_ON(gnttab_interface == NULL); + return gnttab_frames(nr_grant_frames, SPP); +} + static int gnttab_map_frames_v1(xen_pfn_t *frames, unsigned int nr_gframes) { int rc; @@ -955,6 +1053,55 @@ static void gnttab_unmap_frames_v1(void) arch_gnttab_unmap(gnttab_shared.addr, nr_grant_frames); } +static int gnttab_map_frames_v2(xen_pfn_t *frames, unsigned int nr_gframes) +{ + uint64_t *sframes; + unsigned int nr_sframes; + struct gnttab_get_status_frames getframes; + int rc; + + nr_sframes = nr_status_frames(nr_gframes); + + /* No need for kzalloc as it is initialized in following hypercall + * GNTTABOP_get_status_frames. + */ + sframes = kmalloc_array(nr_sframes, sizeof(uint64_t), GFP_ATOMIC); + if (!sframes) + return -ENOMEM; + + getframes.dom = DOMID_SELF; + getframes.nr_frames = nr_sframes; + set_xen_guest_handle(getframes.frame_list, sframes); + + rc = HYPERVISOR_grant_table_op(GNTTABOP_get_status_frames, + &getframes, 1); + if (rc == -ENOSYS) { + kfree(sframes); + return -ENOSYS; + } + + BUG_ON(rc || getframes.status); + + rc = arch_gnttab_map_status(sframes, nr_sframes, + nr_status_frames(gnttab_max_grant_frames()), + &grstatus); + BUG_ON(rc); + kfree(sframes); + + rc = arch_gnttab_map_shared(frames, nr_gframes, + gnttab_max_grant_frames(), + &gnttab_shared.addr); + BUG_ON(rc); + + return 0; +} + +static void gnttab_unmap_frames_v2(void) +{ + arch_gnttab_unmap(gnttab_shared.addr, nr_grant_frames); + arch_gnttab_unmap(grstatus, nr_status_frames(nr_grant_frames)); +} + static int gnttab_map(unsigned int start_idx, unsigned int end_idx) { struct gnttab_setup_table setup; @@ -1014,6 +1161,9 @@ static int gnttab_map(unsigned int start_idx, unsigned int end_idx) } static const struct gnttab_ops gnttab_v1_ops = { + .version = 1, + .grefs_per_grant_frame = XEN_PAGE_SIZE / + sizeof(struct grant_entry_v1), .map_frames = gnttab_map_frames_v1, .unmap_frames = gnttab_unmap_frames_v1, .update_entry = gnttab_update_entry_v1, @@ -1022,14 +1172,56 @@ static const struct gnttab_ops gnttab_v1_ops = { .query_foreign_access = gnttab_query_foreign_access_v1, }; -static void gnttab_request_version(void) +static const struct gnttab_ops gnttab_v2_ops = { + .version = 2, + .grefs_per_grant_frame = XEN_PAGE_SIZE / + sizeof(union grant_entry_v2), + .map_frames = gnttab_map_frames_v2, + .unmap_frames = gnttab_unmap_frames_v2, + .update_entry = gnttab_update_entry_v2, + .end_foreign_access_ref = gnttab_end_foreign_access_ref_v2, + .end_foreign_transfer_ref = gnttab_end_foreign_transfer_ref_v2, + .query_foreign_access = gnttab_query_foreign_access_v2, +}; + +static bool gnttab_need_v2(void) { - /* Only version 1 is used, which will always be available. */ - grant_table_version = 1; - grefs_per_grant_frame = XEN_PAGE_SIZE / sizeof(struct grant_entry_v1); - gnttab_interface = &gnttab_v1_ops; +#ifdef CONFIG_X86 + uint32_t base, width; + + if (xen_pv_domain()) { + base = xen_cpuid_base(); + if (cpuid_eax(base) < 5) + return false; /* Information not available, use V1. */ + width = cpuid_ebx(base + 5) & + XEN_CPUID_MACHINE_ADDRESS_WIDTH_MASK; + return width > 32 + PAGE_SHIFT; + } +#endif + return !!(max_possible_pfn >> 32); +} - pr_info("Grant tables using version %d layout\n", grant_table_version); +static void gnttab_request_version(void) +{ + long rc; + struct gnttab_set_version gsv; + + if (gnttab_need_v2()) + gsv.version = 2; + else + gsv.version = 1; + + /* Boot parameter overrides automatic selection. */ + if (xen_gnttab_version >= 1 && xen_gnttab_version <= 2) + gsv.version = xen_gnttab_version; + + rc = HYPERVISOR_grant_table_op(GNTTABOP_set_version, &gsv, 1); + if (rc == 0 && gsv.version == 2) + gnttab_interface = &gnttab_v2_ops; + else + gnttab_interface = &gnttab_v1_ops; + pr_info("Grant tables using version %d layout\n", + gnttab_interface->version); } static int gnttab_setup(void) @@ -1069,10 +1261,10 @@ static int gnttab_expand(unsigned int req_entries) int rc; unsigned int cur, extra; - BUG_ON(grefs_per_grant_frame == 0); + BUG_ON(gnttab_interface == NULL); cur = nr_grant_frames; - extra = ((req_entries + (grefs_per_grant_frame-1)) / - grefs_per_grant_frame); + extra = ((req_entries + gnttab_interface->grefs_per_grant_frame - 1) / + gnttab_interface->grefs_per_grant_frame); if (cur + extra > gnttab_max_grant_frames()) { pr_warn_ratelimited("xen/grant-table: max_grant_frames reached" " cur=%u extra=%u limit=%u" @@ -1104,16 +1296,16 @@ int gnttab_init(void) /* Determine the maximum number of frames required for the * grant reference free list on the current hypervisor. */ - BUG_ON(grefs_per_grant_frame == 0); + BUG_ON(gnttab_interface == NULL); max_nr_glist_frames = (max_nr_grant_frames * - grefs_per_grant_frame / RPP); + gnttab_interface->grefs_per_grant_frame / RPP); gnttab_list = kmalloc(max_nr_glist_frames * sizeof(grant_ref_t *), GFP_KERNEL); if (gnttab_list == NULL) return -ENOMEM; - nr_glist_frames = (nr_grant_frames * grefs_per_grant_frame + RPP - 1) / RPP; + nr_glist_frames = gnttab_frames(nr_grant_frames, RPP); for (i = 0; i < nr_glist_frames; i++) { gnttab_list[i] = (grant_ref_t *)__get_free_page(GFP_KERNEL); if (gnttab_list[i] == NULL) { @@ -1122,7 +1314,8 @@ int gnttab_init(void) } } - ret = arch_gnttab_init(max_nr_grant_frames); + ret = arch_gnttab_init(max_nr_grant_frames, + nr_status_frames(max_nr_grant_frames)); if (ret < 0) goto ini_nomem; @@ -1131,7 +1324,8 @@ int gnttab_init(void) goto ini_nomem; } - nr_init_grefs = nr_grant_frames * grefs_per_grant_frame; + nr_init_grefs = nr_grant_frames * + gnttab_interface->grefs_per_grant_frame; for (i = NR_RESERVED_ENTRIES; i < nr_init_grefs - 1; i++) gnttab_entry(i) = i + 1; diff --git a/drivers/xen/manage.c b/drivers/xen/manage.c index c425d03d37d2..8835065029d3 100644 --- a/drivers/xen/manage.c +++ b/drivers/xen/manage.c @@ -72,18 +72,15 @@ static int xen_suspend(void *data) } gnttab_suspend(); + xen_manage_runstate_time(-1); xen_arch_pre_suspend(); - /* - * This hypercall returns 1 if suspend was cancelled - * or the domain was merely checkpointed, and 0 if it - * is resuming in a new domain. - */ si->cancelled = HYPERVISOR_suspend(xen_pv_domain() ? virt_to_gfn(xen_start_info) : 0); xen_arch_post_suspend(si->cancelled); + xen_manage_runstate_time(si->cancelled ? 1 : 0); gnttab_resume(); if (!si->cancelled) { diff --git a/drivers/xen/privcmd.c b/drivers/xen/privcmd.c index feca75b07fdd..1c909183c42a 100644 --- a/drivers/xen/privcmd.c +++ b/drivers/xen/privcmd.c @@ -191,13 +191,10 @@ static int traverse_pages_block(unsigned nelem, size_t size, void *state) { void *pagedata; - unsigned pageidx; int ret = 0; BUG_ON(size > PAGE_SIZE); - pageidx = PAGE_SIZE; - while (nelem) { int nr = (PAGE_SIZE/size); struct page *page; diff --git a/drivers/xen/pvcalls-back.c b/drivers/xen/pvcalls-back.c index b209cd44bb8d..02cd33c58204 100644 --- a/drivers/xen/pvcalls-back.c +++ b/drivers/xen/pvcalls-back.c @@ -1238,3 +1238,7 @@ static void __exit pvcalls_back_fin(void) } module_exit(pvcalls_back_fin); + +MODULE_DESCRIPTION("Xen PV Calls backend driver"); +MODULE_AUTHOR("Stefano Stabellini <sstabellini@kernel.org>"); +MODULE_LICENSE("GPL"); diff --git a/drivers/xen/pvcalls-front.c b/drivers/xen/pvcalls-front.c new file mode 100644 index 000000000000..40caa92bff33 --- /dev/null +++ b/drivers/xen/pvcalls-front.c @@ -0,0 +1,1278 @@ +/* + * (c) 2017 Stefano Stabellini <stefano@aporeto.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#include <linux/module.h> +#include <linux/net.h> +#include <linux/socket.h> + +#include <net/sock.h> + +#include <xen/events.h> +#include <xen/grant_table.h> +#include <xen/xen.h> +#include <xen/xenbus.h> +#include <xen/interface/io/pvcalls.h> + +#include "pvcalls-front.h" + +#define PVCALLS_INVALID_ID UINT_MAX +#define PVCALLS_RING_ORDER XENBUS_MAX_RING_GRANT_ORDER +#define PVCALLS_NR_RSP_PER_RING __CONST_RING_SIZE(xen_pvcalls, XEN_PAGE_SIZE) +#define PVCALLS_FRONT_MAX_SPIN 5000 + +struct pvcalls_bedata { + struct xen_pvcalls_front_ring ring; + grant_ref_t ref; + int irq; + + struct list_head socket_mappings; + spinlock_t socket_lock; + + wait_queue_head_t inflight_req; + struct xen_pvcalls_response rsp[PVCALLS_NR_RSP_PER_RING]; +}; +/* Only one front/back connection supported. */ +static struct xenbus_device *pvcalls_front_dev; +static atomic_t pvcalls_refcount; + +/* first increment refcount, then proceed */ +#define pvcalls_enter() { \ + atomic_inc(&pvcalls_refcount); \ +} + +/* first complete other operations, then decrement refcount */ +#define pvcalls_exit() { \ + atomic_dec(&pvcalls_refcount); \ +} + +struct sock_mapping { + bool active_socket; + struct list_head list; + struct socket *sock; + union { + struct { + int irq; + grant_ref_t ref; + struct pvcalls_data_intf *ring; + struct pvcalls_data data; + struct mutex in_mutex; + struct mutex out_mutex; + + wait_queue_head_t inflight_conn_req; + } active; + struct { + /* Socket status */ +#define PVCALLS_STATUS_UNINITALIZED 0 +#define PVCALLS_STATUS_BIND 1 +#define PVCALLS_STATUS_LISTEN 2 + uint8_t status; + /* + * Internal state-machine flags. + * Only one accept operation can be inflight for a socket. + * Only one poll operation can be inflight for a given socket. + */ +#define PVCALLS_FLAG_ACCEPT_INFLIGHT 0 +#define PVCALLS_FLAG_POLL_INFLIGHT 1 +#define PVCALLS_FLAG_POLL_RET 2 + uint8_t flags; + uint32_t inflight_req_id; + struct sock_mapping *accept_map; + wait_queue_head_t inflight_accept_req; + } passive; + }; +}; + +static inline int get_request(struct pvcalls_bedata *bedata, int *req_id) +{ + *req_id = bedata->ring.req_prod_pvt & (RING_SIZE(&bedata->ring) - 1); + if (RING_FULL(&bedata->ring) || + bedata->rsp[*req_id].req_id != PVCALLS_INVALID_ID) + return -EAGAIN; + return 0; +} + +static bool pvcalls_front_write_todo(struct sock_mapping *map) +{ + struct pvcalls_data_intf *intf = map->active.ring; + RING_IDX cons, prod, size = XEN_FLEX_RING_SIZE(PVCALLS_RING_ORDER); + int32_t error; + + error = intf->out_error; + if (error == -ENOTCONN) + return false; + if (error != 0) + return true; + + cons = intf->out_cons; + prod = intf->out_prod; + return !!(size - pvcalls_queued(prod, cons, size)); +} + +static bool pvcalls_front_read_todo(struct sock_mapping *map) +{ + struct pvcalls_data_intf *intf = map->active.ring; + RING_IDX cons, prod; + int32_t error; + + cons = intf->in_cons; + prod = intf->in_prod; + error = intf->in_error; + return (error != 0 || + pvcalls_queued(prod, cons, + XEN_FLEX_RING_SIZE(PVCALLS_RING_ORDER)) != 0); +} + +static irqreturn_t pvcalls_front_event_handler(int irq, void *dev_id) +{ + struct xenbus_device *dev = dev_id; + struct pvcalls_bedata *bedata; + struct xen_pvcalls_response *rsp; + uint8_t *src, *dst; + int req_id = 0, more = 0, done = 0; + + if (dev == NULL) + return IRQ_HANDLED; + + pvcalls_enter(); + bedata = dev_get_drvdata(&dev->dev); + if (bedata == NULL) { + pvcalls_exit(); + return IRQ_HANDLED; + } + +again: + while (RING_HAS_UNCONSUMED_RESPONSES(&bedata->ring)) { + rsp = RING_GET_RESPONSE(&bedata->ring, bedata->ring.rsp_cons); + + req_id = rsp->req_id; + if (rsp->cmd == PVCALLS_POLL) { + struct sock_mapping *map = (struct sock_mapping *)(uintptr_t) + rsp->u.poll.id; + + clear_bit(PVCALLS_FLAG_POLL_INFLIGHT, + (void *)&map->passive.flags); + /* + * clear INFLIGHT, then set RET. It pairs with + * the checks at the beginning of + * pvcalls_front_poll_passive. + */ + smp_wmb(); + set_bit(PVCALLS_FLAG_POLL_RET, + (void *)&map->passive.flags); + } else { + dst = (uint8_t *)&bedata->rsp[req_id] + + sizeof(rsp->req_id); + src = (uint8_t *)rsp + sizeof(rsp->req_id); + memcpy(dst, src, sizeof(*rsp) - sizeof(rsp->req_id)); + /* + * First copy the rest of the data, then req_id. It is + * paired with the barrier when accessing bedata->rsp. + */ + smp_wmb(); + bedata->rsp[req_id].req_id = req_id; + } + + done = 1; + bedata->ring.rsp_cons++; + } + + RING_FINAL_CHECK_FOR_RESPONSES(&bedata->ring, more); + if (more) + goto again; + if (done) + wake_up(&bedata->inflight_req); + pvcalls_exit(); + return IRQ_HANDLED; +} + +static void pvcalls_front_free_map(struct pvcalls_bedata *bedata, + struct sock_mapping *map) +{ + int i; + + unbind_from_irqhandler(map->active.irq, map); + + spin_lock(&bedata->socket_lock); + if (!list_empty(&map->list)) + list_del_init(&map->list); + spin_unlock(&bedata->socket_lock); + + for (i = 0; i < (1 << PVCALLS_RING_ORDER); i++) + gnttab_end_foreign_access(map->active.ring->ref[i], 0, 0); + gnttab_end_foreign_access(map->active.ref, 0, 0); + free_page((unsigned long)map->active.ring); + + kfree(map); +} + +static irqreturn_t pvcalls_front_conn_handler(int irq, void *sock_map) +{ + struct sock_mapping *map = sock_map; + + if (map == NULL) + return IRQ_HANDLED; + + wake_up_interruptible(&map->active.inflight_conn_req); + + return IRQ_HANDLED; +} + +int pvcalls_front_socket(struct socket *sock) +{ + struct pvcalls_bedata *bedata; + struct sock_mapping *map = NULL; + struct xen_pvcalls_request *req; + int notify, req_id, ret; + + /* + * PVCalls only supports domain AF_INET, + * type SOCK_STREAM and protocol 0 sockets for now. + * + * Check socket type here, AF_INET and protocol checks are done + * by the caller. + */ + if (sock->type != SOCK_STREAM) + return -EOPNOTSUPP; + + pvcalls_enter(); + if (!pvcalls_front_dev) { + pvcalls_exit(); + return -EACCES; + } + bedata = dev_get_drvdata(&pvcalls_front_dev->dev); + + map = kzalloc(sizeof(*map), GFP_KERNEL); + if (map == NULL) { + pvcalls_exit(); + return -ENOMEM; + } + + spin_lock(&bedata->socket_lock); + + ret = get_request(bedata, &req_id); + if (ret < 0) { + kfree(map); + spin_unlock(&bedata->socket_lock); + pvcalls_exit(); + return ret; + } + + /* + * sock->sk->sk_send_head is not used for ip sockets: reuse the + * field to store a pointer to the struct sock_mapping + * corresponding to the socket. This way, we can easily get the + * struct sock_mapping from the struct socket. + */ + sock->sk->sk_send_head = (void *)map; + list_add_tail(&map->list, &bedata->socket_mappings); + + req = RING_GET_REQUEST(&bedata->ring, req_id); + req->req_id = req_id; + req->cmd = PVCALLS_SOCKET; + req->u.socket.id = (uintptr_t) map; + req->u.socket.domain = AF_INET; + req->u.socket.type = SOCK_STREAM; + req->u.socket.protocol = IPPROTO_IP; + + bedata->ring.req_prod_pvt++; + RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&bedata->ring, notify); + spin_unlock(&bedata->socket_lock); + if (notify) + notify_remote_via_irq(bedata->irq); + + wait_event(bedata->inflight_req, + READ_ONCE(bedata->rsp[req_id].req_id) == req_id); + + /* read req_id, then the content */ + smp_rmb(); + ret = bedata->rsp[req_id].ret; + bedata->rsp[req_id].req_id = PVCALLS_INVALID_ID; + + pvcalls_exit(); + return ret; +} + +static int create_active(struct sock_mapping *map, int *evtchn) +{ + void *bytes; + int ret = -ENOMEM, irq = -1, i; + + *evtchn = -1; + init_waitqueue_head(&map->active.inflight_conn_req); + + map->active.ring = (struct pvcalls_data_intf *) + __get_free_page(GFP_KERNEL | __GFP_ZERO); + if (map->active.ring == NULL) + goto out_error; + map->active.ring->ring_order = PVCALLS_RING_ORDER; + bytes = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, + PVCALLS_RING_ORDER); + if (bytes == NULL) + goto out_error; + for (i = 0; i < (1 << PVCALLS_RING_ORDER); i++) + map->active.ring->ref[i] = gnttab_grant_foreign_access( + pvcalls_front_dev->otherend_id, + pfn_to_gfn(virt_to_pfn(bytes) + i), 0); + + map->active.ref = gnttab_grant_foreign_access( + pvcalls_front_dev->otherend_id, + pfn_to_gfn(virt_to_pfn((void *)map->active.ring)), 0); + + map->active.data.in = bytes; + map->active.data.out = bytes + + XEN_FLEX_RING_SIZE(PVCALLS_RING_ORDER); + + ret = xenbus_alloc_evtchn(pvcalls_front_dev, evtchn); + if (ret) + goto out_error; + irq = bind_evtchn_to_irqhandler(*evtchn, pvcalls_front_conn_handler, + 0, "pvcalls-frontend", map); + if (irq < 0) { + ret = irq; + goto out_error; + } + + map->active.irq = irq; + map->active_socket = true; + mutex_init(&map->active.in_mutex); + mutex_init(&map->active.out_mutex); + + return 0; + +out_error: + if (*evtchn >= 0) + xenbus_free_evtchn(pvcalls_front_dev, *evtchn); + kfree(map->active.data.in); + kfree(map->active.ring); + return ret; +} + +int pvcalls_front_connect(struct socket *sock, struct sockaddr *addr, + int addr_len, int flags) +{ + struct pvcalls_bedata *bedata; + struct sock_mapping *map = NULL; + struct xen_pvcalls_request *req; + int notify, req_id, ret, evtchn; + + if (addr->sa_family != AF_INET || sock->type != SOCK_STREAM) + return -EOPNOTSUPP; + + pvcalls_enter(); + if (!pvcalls_front_dev) { + pvcalls_exit(); + return -ENOTCONN; + } + + bedata = dev_get_drvdata(&pvcalls_front_dev->dev); + + map = (struct sock_mapping *)sock->sk->sk_send_head; + if (!map) { + pvcalls_exit(); + return -ENOTSOCK; + } + + spin_lock(&bedata->socket_lock); + ret = get_request(bedata, &req_id); + if (ret < 0) { + spin_unlock(&bedata->socket_lock); + pvcalls_exit(); + return ret; + } + ret = create_active(map, &evtchn); + if (ret < 0) { + spin_unlock(&bedata->socket_lock); + pvcalls_exit(); + return ret; + } + + req = RING_GET_REQUEST(&bedata->ring, req_id); + req->req_id = req_id; + req->cmd = PVCALLS_CONNECT; + req->u.connect.id = (uintptr_t)map; + req->u.connect.len = addr_len; + req->u.connect.flags = flags; + req->u.connect.ref = map->active.ref; + req->u.connect.evtchn = evtchn; + memcpy(req->u.connect.addr, addr, sizeof(*addr)); + + map->sock = sock; + + bedata->ring.req_prod_pvt++; + RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&bedata->ring, notify); + spin_unlock(&bedata->socket_lock); + + if (notify) + notify_remote_via_irq(bedata->irq); + + wait_event(bedata->inflight_req, + READ_ONCE(bedata->rsp[req_id].req_id) == req_id); + + /* read req_id, then the content */ + smp_rmb(); + ret = bedata->rsp[req_id].ret; + bedata->rsp[req_id].req_id = PVCALLS_INVALID_ID; + pvcalls_exit(); + return ret; +} + +static int __write_ring(struct pvcalls_data_intf *intf, + struct pvcalls_data *data, + struct iov_iter *msg_iter, + int len) +{ + RING_IDX cons, prod, size, masked_prod, masked_cons; + RING_IDX array_size = XEN_FLEX_RING_SIZE(PVCALLS_RING_ORDER); + int32_t error; + + error = intf->out_error; + if (error < 0) + return error; + cons = intf->out_cons; + prod = intf->out_prod; + /* read indexes before continuing */ + virt_mb(); + + size = pvcalls_queued(prod, cons, array_size); + if (size >= array_size) + return -EINVAL; + if (len > array_size - size) + len = array_size - size; + + masked_prod = pvcalls_mask(prod, array_size); + masked_cons = pvcalls_mask(cons, array_size); + + if (masked_prod < masked_cons) { + len = copy_from_iter(data->out + masked_prod, len, msg_iter); + } else { + if (len > array_size - masked_prod) { + int ret = copy_from_iter(data->out + masked_prod, + array_size - masked_prod, msg_iter); + if (ret != array_size - masked_prod) { + len = ret; + goto out; + } + len = ret + copy_from_iter(data->out, len - ret, msg_iter); + } else { + len = copy_from_iter(data->out + masked_prod, len, msg_iter); + } + } +out: + /* write to ring before updating pointer */ + virt_wmb(); + intf->out_prod += len; + + return len; +} + +int pvcalls_front_sendmsg(struct socket *sock, struct msghdr *msg, + size_t len) +{ + struct pvcalls_bedata *bedata; + struct sock_mapping *map; + int sent, tot_sent = 0; + int count = 0, flags; + + flags = msg->msg_flags; + if (flags & (MSG_CONFIRM|MSG_DONTROUTE|MSG_EOR|MSG_OOB)) + return -EOPNOTSUPP; + + pvcalls_enter(); + if (!pvcalls_front_dev) { + pvcalls_exit(); + return -ENOTCONN; + } + bedata = dev_get_drvdata(&pvcalls_front_dev->dev); + + map = (struct sock_mapping *) sock->sk->sk_send_head; + if (!map) { + pvcalls_exit(); + return -ENOTSOCK; + } + + mutex_lock(&map->active.out_mutex); + if ((flags & MSG_DONTWAIT) && !pvcalls_front_write_todo(map)) { + mutex_unlock(&map->active.out_mutex); + pvcalls_exit(); + return -EAGAIN; + } + if (len > INT_MAX) + len = INT_MAX; + +again: + count++; + sent = __write_ring(map->active.ring, + &map->active.data, &msg->msg_iter, + len); + if (sent > 0) { + len -= sent; + tot_sent += sent; + notify_remote_via_irq(map->active.irq); + } + if (sent >= 0 && len > 0 && count < PVCALLS_FRONT_MAX_SPIN) + goto again; + if (sent < 0) + tot_sent = sent; + + mutex_unlock(&map->active.out_mutex); + pvcalls_exit(); + return tot_sent; +} + +static int __read_ring(struct pvcalls_data_intf *intf, + struct pvcalls_data *data, + struct iov_iter *msg_iter, + size_t len, int flags) +{ + RING_IDX cons, prod, size, masked_prod, masked_cons; + RING_IDX array_size = XEN_FLEX_RING_SIZE(PVCALLS_RING_ORDER); + int32_t error; + + cons = intf->in_cons; + prod = intf->in_prod; + error = intf->in_error; + /* get pointers before reading from the ring */ + virt_rmb(); + if (error < 0) + return error; + + size = pvcalls_queued(prod, cons, array_size); + masked_prod = pvcalls_mask(prod, array_size); + masked_cons = pvcalls_mask(cons, array_size); + + if (size == 0) + return 0; + + if (len > size) + len = size; + + if (masked_prod > masked_cons) { + len = copy_to_iter(data->in + masked_cons, len, msg_iter); + } else { + if (len > (array_size - masked_cons)) { + int ret = copy_to_iter(data->in + masked_cons, + array_size - masked_cons, msg_iter); + if (ret != array_size - masked_cons) { + len = ret; + goto out; + } + len = ret + copy_to_iter(data->in, len - ret, msg_iter); + } else { + len = copy_to_iter(data->in + masked_cons, len, msg_iter); + } + } +out: + /* read data from the ring before increasing the index */ + virt_mb(); + if (!(flags & MSG_PEEK)) + intf->in_cons += len; + + return len; +} + +int pvcalls_front_recvmsg(struct socket *sock, struct msghdr *msg, size_t len, + int flags) +{ + struct pvcalls_bedata *bedata; + int ret; + struct sock_mapping *map; + + if (flags & (MSG_CMSG_CLOEXEC|MSG_ERRQUEUE|MSG_OOB|MSG_TRUNC)) + return -EOPNOTSUPP; + + pvcalls_enter(); + if (!pvcalls_front_dev) { + pvcalls_exit(); + return -ENOTCONN; + } + bedata = dev_get_drvdata(&pvcalls_front_dev->dev); + + map = (struct sock_mapping *) sock->sk->sk_send_head; + if (!map) { + pvcalls_exit(); + return -ENOTSOCK; + } + + mutex_lock(&map->active.in_mutex); + if (len > XEN_FLEX_RING_SIZE(PVCALLS_RING_ORDER)) + len = XEN_FLEX_RING_SIZE(PVCALLS_RING_ORDER); + + while (!(flags & MSG_DONTWAIT) && !pvcalls_front_read_todo(map)) { + wait_event_interruptible(map->active.inflight_conn_req, + pvcalls_front_read_todo(map)); + } + ret = __read_ring(map->active.ring, &map->active.data, + &msg->msg_iter, len, flags); + + if (ret > 0) + notify_remote_via_irq(map->active.irq); + if (ret == 0) + ret = (flags & MSG_DONTWAIT) ? -EAGAIN : 0; + if (ret == -ENOTCONN) + ret = 0; + + mutex_unlock(&map->active.in_mutex); + pvcalls_exit(); + return ret; +} + +int pvcalls_front_bind(struct socket *sock, struct sockaddr *addr, int addr_len) +{ + struct pvcalls_bedata *bedata; + struct sock_mapping *map = NULL; + struct xen_pvcalls_request *req; + int notify, req_id, ret; + + if (addr->sa_family != AF_INET || sock->type != SOCK_STREAM) + return -EOPNOTSUPP; + + pvcalls_enter(); + if (!pvcalls_front_dev) { + pvcalls_exit(); + return -ENOTCONN; + } + bedata = dev_get_drvdata(&pvcalls_front_dev->dev); + + map = (struct sock_mapping *) sock->sk->sk_send_head; + if (map == NULL) { + pvcalls_exit(); + return -ENOTSOCK; + } + + spin_lock(&bedata->socket_lock); + ret = get_request(bedata, &req_id); + if (ret < 0) { + spin_unlock(&bedata->socket_lock); + pvcalls_exit(); + return ret; + } + req = RING_GET_REQUEST(&bedata->ring, req_id); + req->req_id = req_id; + map->sock = sock; + req->cmd = PVCALLS_BIND; + req->u.bind.id = (uintptr_t)map; + memcpy(req->u.bind.addr, addr, sizeof(*addr)); + req->u.bind.len = addr_len; + + init_waitqueue_head(&map->passive.inflight_accept_req); + + map->active_socket = false; + + bedata->ring.req_prod_pvt++; + RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&bedata->ring, notify); + spin_unlock(&bedata->socket_lock); + if (notify) + notify_remote_via_irq(bedata->irq); + + wait_event(bedata->inflight_req, + READ_ONCE(bedata->rsp[req_id].req_id) == req_id); + + /* read req_id, then the content */ + smp_rmb(); + ret = bedata->rsp[req_id].ret; + bedata->rsp[req_id].req_id = PVCALLS_INVALID_ID; + + map->passive.status = PVCALLS_STATUS_BIND; + pvcalls_exit(); + return 0; +} + +int pvcalls_front_listen(struct socket *sock, int backlog) +{ + struct pvcalls_bedata *bedata; + struct sock_mapping *map; + struct xen_pvcalls_request *req; + int notify, req_id, ret; + + pvcalls_enter(); + if (!pvcalls_front_dev) { + pvcalls_exit(); + return -ENOTCONN; + } + bedata = dev_get_drvdata(&pvcalls_front_dev->dev); + + map = (struct sock_mapping *) sock->sk->sk_send_head; + if (!map) { + pvcalls_exit(); + return -ENOTSOCK; + } + + if (map->passive.status != PVCALLS_STATUS_BIND) { + pvcalls_exit(); + return -EOPNOTSUPP; + } + + spin_lock(&bedata->socket_lock); + ret = get_request(bedata, &req_id); + if (ret < 0) { + spin_unlock(&bedata->socket_lock); + pvcalls_exit(); + return ret; + } + req = RING_GET_REQUEST(&bedata->ring, req_id); + req->req_id = req_id; + req->cmd = PVCALLS_LISTEN; + req->u.listen.id = (uintptr_t) map; + req->u.listen.backlog = backlog; + + bedata->ring.req_prod_pvt++; + RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&bedata->ring, notify); + spin_unlock(&bedata->socket_lock); + if (notify) + notify_remote_via_irq(bedata->irq); + + wait_event(bedata->inflight_req, + READ_ONCE(bedata->rsp[req_id].req_id) == req_id); + + /* read req_id, then the content */ + smp_rmb(); + ret = bedata->rsp[req_id].ret; + bedata->rsp[req_id].req_id = PVCALLS_INVALID_ID; + + map->passive.status = PVCALLS_STATUS_LISTEN; + pvcalls_exit(); + return ret; +} + +int pvcalls_front_accept(struct socket *sock, struct socket *newsock, int flags) +{ + struct pvcalls_bedata *bedata; + struct sock_mapping *map; + struct sock_mapping *map2 = NULL; + struct xen_pvcalls_request *req; + int notify, req_id, ret, evtchn, nonblock; + + pvcalls_enter(); + if (!pvcalls_front_dev) { + pvcalls_exit(); + return -ENOTCONN; + } + bedata = dev_get_drvdata(&pvcalls_front_dev->dev); + + map = (struct sock_mapping *) sock->sk->sk_send_head; + if (!map) { + pvcalls_exit(); + return -ENOTSOCK; + } + + if (map->passive.status != PVCALLS_STATUS_LISTEN) { + pvcalls_exit(); + return -EINVAL; + } + + nonblock = flags & SOCK_NONBLOCK; + /* + * Backend only supports 1 inflight accept request, will return + * errors for the others + */ + if (test_and_set_bit(PVCALLS_FLAG_ACCEPT_INFLIGHT, + (void *)&map->passive.flags)) { + req_id = READ_ONCE(map->passive.inflight_req_id); + if (req_id != PVCALLS_INVALID_ID && + READ_ONCE(bedata->rsp[req_id].req_id) == req_id) { + map2 = map->passive.accept_map; + goto received; + } + if (nonblock) { + pvcalls_exit(); + return -EAGAIN; + } + if (wait_event_interruptible(map->passive.inflight_accept_req, + !test_and_set_bit(PVCALLS_FLAG_ACCEPT_INFLIGHT, + (void *)&map->passive.flags))) { + pvcalls_exit(); + return -EINTR; + } + } + + spin_lock(&bedata->socket_lock); + ret = get_request(bedata, &req_id); + if (ret < 0) { + clear_bit(PVCALLS_FLAG_ACCEPT_INFLIGHT, + (void *)&map->passive.flags); + spin_unlock(&bedata->socket_lock); + pvcalls_exit(); + return ret; + } + map2 = kzalloc(sizeof(*map2), GFP_KERNEL); + if (map2 == NULL) { + clear_bit(PVCALLS_FLAG_ACCEPT_INFLIGHT, + (void *)&map->passive.flags); + spin_unlock(&bedata->socket_lock); + pvcalls_exit(); + return -ENOMEM; + } + ret = create_active(map2, &evtchn); + if (ret < 0) { + kfree(map2); + clear_bit(PVCALLS_FLAG_ACCEPT_INFLIGHT, + (void *)&map->passive.flags); + spin_unlock(&bedata->socket_lock); + pvcalls_exit(); + return ret; + } + list_add_tail(&map2->list, &bedata->socket_mappings); + + req = RING_GET_REQUEST(&bedata->ring, req_id); + req->req_id = req_id; + req->cmd = PVCALLS_ACCEPT; + req->u.accept.id = (uintptr_t) map; + req->u.accept.ref = map2->active.ref; + req->u.accept.id_new = (uintptr_t) map2; + req->u.accept.evtchn = evtchn; + map->passive.accept_map = map2; + + bedata->ring.req_prod_pvt++; + RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&bedata->ring, notify); + spin_unlock(&bedata->socket_lock); + if (notify) + notify_remote_via_irq(bedata->irq); + /* We could check if we have received a response before returning. */ + if (nonblock) { + WRITE_ONCE(map->passive.inflight_req_id, req_id); + pvcalls_exit(); + return -EAGAIN; + } + + if (wait_event_interruptible(bedata->inflight_req, + READ_ONCE(bedata->rsp[req_id].req_id) == req_id)) { + pvcalls_exit(); + return -EINTR; + } + /* read req_id, then the content */ + smp_rmb(); + +received: + map2->sock = newsock; + newsock->sk = kzalloc(sizeof(*newsock->sk), GFP_KERNEL); + if (!newsock->sk) { + bedata->rsp[req_id].req_id = PVCALLS_INVALID_ID; + map->passive.inflight_req_id = PVCALLS_INVALID_ID; + clear_bit(PVCALLS_FLAG_ACCEPT_INFLIGHT, + (void *)&map->passive.flags); + pvcalls_front_free_map(bedata, map2); + pvcalls_exit(); + return -ENOMEM; + } + newsock->sk->sk_send_head = (void *)map2; + + ret = bedata->rsp[req_id].ret; + bedata->rsp[req_id].req_id = PVCALLS_INVALID_ID; + map->passive.inflight_req_id = PVCALLS_INVALID_ID; + + clear_bit(PVCALLS_FLAG_ACCEPT_INFLIGHT, (void *)&map->passive.flags); + wake_up(&map->passive.inflight_accept_req); + + pvcalls_exit(); + return ret; +} + +static unsigned int pvcalls_front_poll_passive(struct file *file, + struct pvcalls_bedata *bedata, + struct sock_mapping *map, + poll_table *wait) +{ + int notify, req_id, ret; + struct xen_pvcalls_request *req; + + if (test_bit(PVCALLS_FLAG_ACCEPT_INFLIGHT, + (void *)&map->passive.flags)) { + uint32_t req_id = READ_ONCE(map->passive.inflight_req_id); + + if (req_id != PVCALLS_INVALID_ID && + READ_ONCE(bedata->rsp[req_id].req_id) == req_id) + return POLLIN | POLLRDNORM; + + poll_wait(file, &map->passive.inflight_accept_req, wait); + return 0; + } + + if (test_and_clear_bit(PVCALLS_FLAG_POLL_RET, + (void *)&map->passive.flags)) + return POLLIN | POLLRDNORM; + + /* + * First check RET, then INFLIGHT. No barriers necessary to + * ensure execution ordering because of the conditional + * instructions creating control dependencies. + */ + + if (test_and_set_bit(PVCALLS_FLAG_POLL_INFLIGHT, + (void *)&map->passive.flags)) { + poll_wait(file, &bedata->inflight_req, wait); + return 0; + } + + spin_lock(&bedata->socket_lock); + ret = get_request(bedata, &req_id); + if (ret < 0) { + spin_unlock(&bedata->socket_lock); + return ret; + } + req = RING_GET_REQUEST(&bedata->ring, req_id); + req->req_id = req_id; + req->cmd = PVCALLS_POLL; + req->u.poll.id = (uintptr_t) map; + + bedata->ring.req_prod_pvt++; + RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&bedata->ring, notify); + spin_unlock(&bedata->socket_lock); + if (notify) + notify_remote_via_irq(bedata->irq); + + poll_wait(file, &bedata->inflight_req, wait); + return 0; +} + +static unsigned int pvcalls_front_poll_active(struct file *file, + struct pvcalls_bedata *bedata, + struct sock_mapping *map, + poll_table *wait) +{ + unsigned int mask = 0; + int32_t in_error, out_error; + struct pvcalls_data_intf *intf = map->active.ring; + + out_error = intf->out_error; + in_error = intf->in_error; + + poll_wait(file, &map->active.inflight_conn_req, wait); + if (pvcalls_front_write_todo(map)) + mask |= POLLOUT | POLLWRNORM; + if (pvcalls_front_read_todo(map)) + mask |= POLLIN | POLLRDNORM; + if (in_error != 0 || out_error != 0) + mask |= POLLERR; + + return mask; +} + +unsigned int pvcalls_front_poll(struct file *file, struct socket *sock, + poll_table *wait) +{ + struct pvcalls_bedata *bedata; + struct sock_mapping *map; + int ret; + + pvcalls_enter(); + if (!pvcalls_front_dev) { + pvcalls_exit(); + return POLLNVAL; + } + bedata = dev_get_drvdata(&pvcalls_front_dev->dev); + + map = (struct sock_mapping *) sock->sk->sk_send_head; + if (!map) { + pvcalls_exit(); + return POLLNVAL; + } + if (map->active_socket) + ret = pvcalls_front_poll_active(file, bedata, map, wait); + else + ret = pvcalls_front_poll_passive(file, bedata, map, wait); + pvcalls_exit(); + return ret; +} + +int pvcalls_front_release(struct socket *sock) +{ + struct pvcalls_bedata *bedata; + struct sock_mapping *map; + int req_id, notify, ret; + struct xen_pvcalls_request *req; + + if (sock->sk == NULL) + return 0; + + pvcalls_enter(); + if (!pvcalls_front_dev) { + pvcalls_exit(); + return -EIO; + } + + bedata = dev_get_drvdata(&pvcalls_front_dev->dev); + + map = (struct sock_mapping *) sock->sk->sk_send_head; + if (map == NULL) { + pvcalls_exit(); + return 0; + } + + spin_lock(&bedata->socket_lock); + ret = get_request(bedata, &req_id); + if (ret < 0) { + spin_unlock(&bedata->socket_lock); + pvcalls_exit(); + return ret; + } + sock->sk->sk_send_head = NULL; + + req = RING_GET_REQUEST(&bedata->ring, req_id); + req->req_id = req_id; + req->cmd = PVCALLS_RELEASE; + req->u.release.id = (uintptr_t)map; + + bedata->ring.req_prod_pvt++; + RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&bedata->ring, notify); + spin_unlock(&bedata->socket_lock); + if (notify) + notify_remote_via_irq(bedata->irq); + + wait_event(bedata->inflight_req, + READ_ONCE(bedata->rsp[req_id].req_id) == req_id); + + if (map->active_socket) { + /* + * Set in_error and wake up inflight_conn_req to force + * recvmsg waiters to exit. + */ + map->active.ring->in_error = -EBADF; + wake_up_interruptible(&map->active.inflight_conn_req); + + /* + * We need to make sure that sendmsg/recvmsg on this socket have + * not started before we've cleared sk_send_head here. The + * easiest (though not optimal) way to guarantee this is to see + * that no pvcall (other than us) is in progress. + */ + while (atomic_read(&pvcalls_refcount) > 1) + cpu_relax(); + + pvcalls_front_free_map(bedata, map); + } else { + spin_lock(&bedata->socket_lock); + list_del(&map->list); + spin_unlock(&bedata->socket_lock); + if (READ_ONCE(map->passive.inflight_req_id) != + PVCALLS_INVALID_ID) { + pvcalls_front_free_map(bedata, + map->passive.accept_map); + } + kfree(map); + } + WRITE_ONCE(bedata->rsp[req_id].req_id, PVCALLS_INVALID_ID); + + pvcalls_exit(); + return 0; +} + +static const struct xenbus_device_id pvcalls_front_ids[] = { + { "pvcalls" }, + { "" } +}; + +static int pvcalls_front_remove(struct xenbus_device *dev) +{ + struct pvcalls_bedata *bedata; + struct sock_mapping *map = NULL, *n; + + bedata = dev_get_drvdata(&pvcalls_front_dev->dev); + dev_set_drvdata(&dev->dev, NULL); + pvcalls_front_dev = NULL; + if (bedata->irq >= 0) + unbind_from_irqhandler(bedata->irq, dev); + + list_for_each_entry_safe(map, n, &bedata->socket_mappings, list) { + map->sock->sk->sk_send_head = NULL; + if (map->active_socket) { + map->active.ring->in_error = -EBADF; + wake_up_interruptible(&map->active.inflight_conn_req); + } + } + + smp_mb(); + while (atomic_read(&pvcalls_refcount) > 0) + cpu_relax(); + list_for_each_entry_safe(map, n, &bedata->socket_mappings, list) { + if (map->active_socket) { + /* No need to lock, refcount is 0 */ + pvcalls_front_free_map(bedata, map); + } else { + list_del(&map->list); + kfree(map); + } + } + if (bedata->ref >= 0) + gnttab_end_foreign_access(bedata->ref, 0, 0); + kfree(bedata->ring.sring); + kfree(bedata); + xenbus_switch_state(dev, XenbusStateClosed); + return 0; +} + +static int pvcalls_front_probe(struct xenbus_device *dev, + const struct xenbus_device_id *id) +{ + int ret = -ENOMEM, evtchn, i; + unsigned int max_page_order, function_calls, len; + char *versions; + grant_ref_t gref_head = 0; + struct xenbus_transaction xbt; + struct pvcalls_bedata *bedata = NULL; + struct xen_pvcalls_sring *sring; + + if (pvcalls_front_dev != NULL) { + dev_err(&dev->dev, "only one PV Calls connection supported\n"); + return -EINVAL; + } + + versions = xenbus_read(XBT_NIL, dev->otherend, "versions", &len); + if (!len) + return -EINVAL; + if (strcmp(versions, "1")) { + kfree(versions); + return -EINVAL; + } + kfree(versions); + max_page_order = xenbus_read_unsigned(dev->otherend, + "max-page-order", 0); + if (max_page_order < PVCALLS_RING_ORDER) + return -ENODEV; + function_calls = xenbus_read_unsigned(dev->otherend, + "function-calls", 0); + /* See XENBUS_FUNCTIONS_CALLS in pvcalls.h */ + if (function_calls != 1) + return -ENODEV; + pr_info("%s max-page-order is %u\n", __func__, max_page_order); + + bedata = kzalloc(sizeof(struct pvcalls_bedata), GFP_KERNEL); + if (!bedata) + return -ENOMEM; + + dev_set_drvdata(&dev->dev, bedata); + pvcalls_front_dev = dev; + init_waitqueue_head(&bedata->inflight_req); + INIT_LIST_HEAD(&bedata->socket_mappings); + spin_lock_init(&bedata->socket_lock); + bedata->irq = -1; + bedata->ref = -1; + + for (i = 0; i < PVCALLS_NR_RSP_PER_RING; i++) + bedata->rsp[i].req_id = PVCALLS_INVALID_ID; + + sring = (struct xen_pvcalls_sring *) __get_free_page(GFP_KERNEL | + __GFP_ZERO); + if (!sring) + goto error; + SHARED_RING_INIT(sring); + FRONT_RING_INIT(&bedata->ring, sring, XEN_PAGE_SIZE); + + ret = xenbus_alloc_evtchn(dev, &evtchn); + if (ret) + goto error; + + bedata->irq = bind_evtchn_to_irqhandler(evtchn, + pvcalls_front_event_handler, + 0, "pvcalls-frontend", dev); + if (bedata->irq < 0) { + ret = bedata->irq; + goto error; + } + + ret = gnttab_alloc_grant_references(1, &gref_head); + if (ret < 0) + goto error; + ret = gnttab_claim_grant_reference(&gref_head); + if (ret < 0) + goto error; + bedata->ref = ret; + gnttab_grant_foreign_access_ref(bedata->ref, dev->otherend_id, + virt_to_gfn((void *)sring), 0); + + again: + ret = xenbus_transaction_start(&xbt); + if (ret) { + xenbus_dev_fatal(dev, ret, "starting transaction"); + goto error; + } + ret = xenbus_printf(xbt, dev->nodename, "version", "%u", 1); + if (ret) + goto error_xenbus; + ret = xenbus_printf(xbt, dev->nodename, "ring-ref", "%d", bedata->ref); + if (ret) + goto error_xenbus; + ret = xenbus_printf(xbt, dev->nodename, "port", "%u", + evtchn); + if (ret) + goto error_xenbus; + ret = xenbus_transaction_end(xbt, 0); + if (ret) { + if (ret == -EAGAIN) + goto again; + xenbus_dev_fatal(dev, ret, "completing transaction"); + goto error; + } + xenbus_switch_state(dev, XenbusStateInitialised); + + return 0; + + error_xenbus: + xenbus_transaction_end(xbt, 1); + xenbus_dev_fatal(dev, ret, "writing xenstore"); + error: + pvcalls_front_remove(dev); + return ret; +} + +static void pvcalls_front_changed(struct xenbus_device *dev, + enum xenbus_state backend_state) +{ + switch (backend_state) { + case XenbusStateReconfiguring: + case XenbusStateReconfigured: + case XenbusStateInitialising: + case XenbusStateInitialised: + case XenbusStateUnknown: + break; + + case XenbusStateInitWait: + break; + + case XenbusStateConnected: + xenbus_switch_state(dev, XenbusStateConnected); + break; + + case XenbusStateClosed: + if (dev->state == XenbusStateClosed) + break; + /* Missed the backend's CLOSING state */ + /* fall through */ + case XenbusStateClosing: + xenbus_frontend_closed(dev); + break; + } +} + +static struct xenbus_driver pvcalls_front_driver = { + .ids = pvcalls_front_ids, + .probe = pvcalls_front_probe, + .remove = pvcalls_front_remove, + .otherend_changed = pvcalls_front_changed, +}; + +static int __init pvcalls_frontend_init(void) +{ + if (!xen_domain()) + return -ENODEV; + + pr_info("Initialising Xen pvcalls frontend driver\n"); + + return xenbus_register_frontend(&pvcalls_front_driver); +} + +module_init(pvcalls_frontend_init); + +MODULE_DESCRIPTION("Xen PV Calls frontend driver"); +MODULE_AUTHOR("Stefano Stabellini <sstabellini@kernel.org>"); +MODULE_LICENSE("GPL"); diff --git a/drivers/xen/pvcalls-front.h b/drivers/xen/pvcalls-front.h new file mode 100644 index 000000000000..3332978f4fcd --- /dev/null +++ b/drivers/xen/pvcalls-front.h @@ -0,0 +1,28 @@ +#ifndef __PVCALLS_FRONT_H__ +#define __PVCALLS_FRONT_H__ + +#include <linux/net.h> + +int pvcalls_front_socket(struct socket *sock); +int pvcalls_front_connect(struct socket *sock, struct sockaddr *addr, + int addr_len, int flags); +int pvcalls_front_bind(struct socket *sock, + struct sockaddr *addr, + int addr_len); +int pvcalls_front_listen(struct socket *sock, int backlog); +int pvcalls_front_accept(struct socket *sock, + struct socket *newsock, + int flags); +int pvcalls_front_sendmsg(struct socket *sock, + struct msghdr *msg, + size_t len); +int pvcalls_front_recvmsg(struct socket *sock, + struct msghdr *msg, + size_t len, + int flags); +unsigned int pvcalls_front_poll(struct file *file, + struct socket *sock, + poll_table *wait); +int pvcalls_front_release(struct socket *sock); + +#endif diff --git a/drivers/xen/time.c b/drivers/xen/time.c index a63fedbdcbe9..3e741cd1409c 100644 --- a/drivers/xen/time.c +++ b/drivers/xen/time.c @@ -6,6 +6,7 @@ #include <linux/kernel_stat.h> #include <linux/math64.h> #include <linux/gfp.h> +#include <linux/slab.h> #include <asm/paravirt.h> #include <asm/xen/hypervisor.h> @@ -20,6 +21,8 @@ /* runstate info updated by Xen */ static DEFINE_PER_CPU(struct vcpu_runstate_info, xen_runstate); +static DEFINE_PER_CPU(u64[4], old_runstate_time); + /* return an consistent snapshot of 64-bit time/counter value */ static u64 get64(const u64 *p) { @@ -48,8 +51,8 @@ static u64 get64(const u64 *p) return ret; } -static void xen_get_runstate_snapshot_cpu(struct vcpu_runstate_info *res, - unsigned int cpu) +static void xen_get_runstate_snapshot_cpu_delta( + struct vcpu_runstate_info *res, unsigned int cpu) { u64 state_time; struct vcpu_runstate_info *state; @@ -67,6 +70,71 @@ static void xen_get_runstate_snapshot_cpu(struct vcpu_runstate_info *res, (state_time & XEN_RUNSTATE_UPDATE)); } +static void xen_get_runstate_snapshot_cpu(struct vcpu_runstate_info *res, + unsigned int cpu) +{ + int i; + + xen_get_runstate_snapshot_cpu_delta(res, cpu); + + for (i = 0; i < 4; i++) + res->time[i] += per_cpu(old_runstate_time, cpu)[i]; +} + +void xen_manage_runstate_time(int action) +{ + static struct vcpu_runstate_info *runstate_delta; + struct vcpu_runstate_info state; + int cpu, i; + + switch (action) { + case -1: /* backup runstate time before suspend */ + if (unlikely(runstate_delta)) + pr_warn_once("%s: memory leak as runstate_delta is not NULL\n", + __func__); + + runstate_delta = kmalloc_array(num_possible_cpus(), + sizeof(*runstate_delta), + GFP_ATOMIC); + if (unlikely(!runstate_delta)) { + pr_warn("%s: failed to allocate runstate_delta\n", + __func__); + return; + } + + for_each_possible_cpu(cpu) { + xen_get_runstate_snapshot_cpu_delta(&state, cpu); + memcpy(runstate_delta[cpu].time, state.time, + sizeof(runstate_delta[cpu].time)); + } + + break; + + case 0: /* backup runstate time after resume */ + if (unlikely(!runstate_delta)) { + pr_warn("%s: cannot accumulate runstate time as runstate_delta is NULL\n", + __func__); + return; + } + + for_each_possible_cpu(cpu) { + for (i = 0; i < 4; i++) + per_cpu(old_runstate_time, cpu)[i] += + runstate_delta[cpu].time[i]; + } + + break; + + default: /* do not accumulate runstate time for checkpointing */ + break; + } + + if (action != -1 && runstate_delta) { + kfree(runstate_delta); + runstate_delta = NULL; + } +} + /* * Runstate accounting */ diff --git a/drivers/xen/xenbus/xenbus_probe_frontend.c b/drivers/xen/xenbus/xenbus_probe_frontend.c index 19e45ce21f89..07896f4b2736 100644 --- a/drivers/xen/xenbus/xenbus_probe_frontend.c +++ b/drivers/xen/xenbus/xenbus_probe_frontend.c @@ -379,10 +379,12 @@ static void xenbus_reset_frontend(char *fe, char *be, int be_state) case XenbusStateConnected: xenbus_printf(XBT_NIL, fe, "state", "%d", XenbusStateClosing); xenbus_reset_wait_for_backend(be, XenbusStateClosing); + /* fall through */ case XenbusStateClosing: xenbus_printf(XBT_NIL, fe, "state", "%d", XenbusStateClosed); xenbus_reset_wait_for_backend(be, XenbusStateClosed); + /* fall through */ case XenbusStateClosed: xenbus_printf(XBT_NIL, fe, "state", "%d", XenbusStateInitialising); |