diff options
Diffstat (limited to 'arch/x86/kvm')
| -rw-r--r-- | arch/x86/kvm/Makefile | 2 | ||||
| -rw-r--r-- | arch/x86/kvm/hyperv.c | 91 | ||||
| -rw-r--r-- | arch/x86/kvm/hyperv.h | 1 | ||||
| -rw-r--r-- | arch/x86/kvm/svm/nested.c | 1 | ||||
| -rw-r--r-- | arch/x86/kvm/svm/pmu.c | 8 | ||||
| -rw-r--r-- | arch/x86/kvm/svm/sev.c | 83 | ||||
| -rw-r--r-- | arch/x86/kvm/svm/svm.h | 1 | ||||
| -rw-r--r-- | arch/x86/kvm/x86.c | 170 | ||||
| -rw-r--r-- | arch/x86/kvm/x86.h | 1 |
9 files changed, 264 insertions, 94 deletions
diff --git a/arch/x86/kvm/Makefile b/arch/x86/kvm/Makefile index 87f514c36eae..c589db5d91b3 100644 --- a/arch/x86/kvm/Makefile +++ b/arch/x86/kvm/Makefile @@ -1,6 +1,6 @@ # SPDX-License-Identifier: GPL-2.0 -ccflags-y += -Iarch/x86/kvm +ccflags-y += -I $(srctree)/arch/x86/kvm ccflags-$(CONFIG_KVM_WERROR) += -Werror ifeq ($(CONFIG_FRAME_POINTER),y) diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c index 58fa8c029867..f98370a39936 100644 --- a/arch/x86/kvm/hyperv.c +++ b/arch/x86/kvm/hyperv.c @@ -520,10 +520,10 @@ static u64 get_time_ref_counter(struct kvm *kvm) u64 tsc; /* - * The guest has not set up the TSC page or the clock isn't - * stable, fall back to get_kvmclock_ns. + * Fall back to get_kvmclock_ns() when TSC page hasn't been set up, + * is broken, disabled or being updated. */ - if (!hv->tsc_ref.tsc_sequence) + if (hv->hv_tsc_page_status != HV_TSC_PAGE_SET) return div_u64(get_kvmclock_ns(kvm), 100); vcpu = kvm_get_vcpu(kvm, 0); @@ -1077,6 +1077,21 @@ static bool compute_tsc_page_parameters(struct pvclock_vcpu_time_info *hv_clock, return true; } +/* + * Don't touch TSC page values if the guest has opted for TSC emulation after + * migration. KVM doesn't fully support reenlightenment notifications and TSC + * access emulation and Hyper-V is known to expect the values in TSC page to + * stay constant before TSC access emulation is disabled from guest side + * (HV_X64_MSR_TSC_EMULATION_STATUS). KVM userspace is expected to preserve TSC + * frequency and guest visible TSC value across migration (and prevent it when + * TSC scaling is unsupported). + */ +static inline bool tsc_page_update_unsafe(struct kvm_hv *hv) +{ + return (hv->hv_tsc_page_status != HV_TSC_PAGE_GUEST_CHANGED) && + hv->hv_tsc_emulation_control; +} + void kvm_hv_setup_tsc_page(struct kvm *kvm, struct pvclock_vcpu_time_info *hv_clock) { @@ -1087,7 +1102,8 @@ void kvm_hv_setup_tsc_page(struct kvm *kvm, BUILD_BUG_ON(sizeof(tsc_seq) != sizeof(hv->tsc_ref.tsc_sequence)); BUILD_BUG_ON(offsetof(struct ms_hyperv_tsc_page, tsc_sequence) != 0); - if (!(hv->hv_tsc_page & HV_X64_MSR_TSC_REFERENCE_ENABLE)) + if (hv->hv_tsc_page_status == HV_TSC_PAGE_BROKEN || + hv->hv_tsc_page_status == HV_TSC_PAGE_UNSET) return; mutex_lock(&hv->hv_lock); @@ -1101,7 +1117,15 @@ void kvm_hv_setup_tsc_page(struct kvm *kvm, */ if (unlikely(kvm_read_guest(kvm, gfn_to_gpa(gfn), &tsc_seq, sizeof(tsc_seq)))) + goto out_err; + + if (tsc_seq && tsc_page_update_unsafe(hv)) { + if (kvm_read_guest(kvm, gfn_to_gpa(gfn), &hv->tsc_ref, sizeof(hv->tsc_ref))) + goto out_err; + + hv->hv_tsc_page_status = HV_TSC_PAGE_SET; goto out_unlock; + } /* * While we're computing and writing the parameters, force the @@ -1110,15 +1134,15 @@ void kvm_hv_setup_tsc_page(struct kvm *kvm, hv->tsc_ref.tsc_sequence = 0; if (kvm_write_guest(kvm, gfn_to_gpa(gfn), &hv->tsc_ref, sizeof(hv->tsc_ref.tsc_sequence))) - goto out_unlock; + goto out_err; if (!compute_tsc_page_parameters(hv_clock, &hv->tsc_ref)) - goto out_unlock; + goto out_err; /* Ensure sequence is zero before writing the rest of the struct. */ smp_wmb(); if (kvm_write_guest(kvm, gfn_to_gpa(gfn), &hv->tsc_ref, sizeof(hv->tsc_ref))) - goto out_unlock; + goto out_err; /* * Now switch to the TSC page mechanism by writing the sequence. @@ -1131,8 +1155,45 @@ void kvm_hv_setup_tsc_page(struct kvm *kvm, smp_wmb(); hv->tsc_ref.tsc_sequence = tsc_seq; - kvm_write_guest(kvm, gfn_to_gpa(gfn), - &hv->tsc_ref, sizeof(hv->tsc_ref.tsc_sequence)); + if (kvm_write_guest(kvm, gfn_to_gpa(gfn), + &hv->tsc_ref, sizeof(hv->tsc_ref.tsc_sequence))) + goto out_err; + + hv->hv_tsc_page_status = HV_TSC_PAGE_SET; + goto out_unlock; + +out_err: + hv->hv_tsc_page_status = HV_TSC_PAGE_BROKEN; +out_unlock: + mutex_unlock(&hv->hv_lock); +} + +void kvm_hv_invalidate_tsc_page(struct kvm *kvm) +{ + struct kvm_hv *hv = to_kvm_hv(kvm); + u64 gfn; + + if (hv->hv_tsc_page_status == HV_TSC_PAGE_BROKEN || + hv->hv_tsc_page_status == HV_TSC_PAGE_UNSET || + tsc_page_update_unsafe(hv)) + return; + + mutex_lock(&hv->hv_lock); + + if (!(hv->hv_tsc_page & HV_X64_MSR_TSC_REFERENCE_ENABLE)) + goto out_unlock; + + /* Preserve HV_TSC_PAGE_GUEST_CHANGED/HV_TSC_PAGE_HOST_CHANGED states */ + if (hv->hv_tsc_page_status == HV_TSC_PAGE_SET) + hv->hv_tsc_page_status = HV_TSC_PAGE_UPDATING; + + gfn = hv->hv_tsc_page >> HV_X64_MSR_TSC_REFERENCE_ADDRESS_SHIFT; + + hv->tsc_ref.tsc_sequence = 0; + if (kvm_write_guest(kvm, gfn_to_gpa(gfn), + &hv->tsc_ref, sizeof(hv->tsc_ref.tsc_sequence))) + hv->hv_tsc_page_status = HV_TSC_PAGE_BROKEN; + out_unlock: mutex_unlock(&hv->hv_lock); } @@ -1193,8 +1254,15 @@ static int kvm_hv_set_msr_pw(struct kvm_vcpu *vcpu, u32 msr, u64 data, } case HV_X64_MSR_REFERENCE_TSC: hv->hv_tsc_page = data; - if (hv->hv_tsc_page & HV_X64_MSR_TSC_REFERENCE_ENABLE) + if (hv->hv_tsc_page & HV_X64_MSR_TSC_REFERENCE_ENABLE) { + if (!host) + hv->hv_tsc_page_status = HV_TSC_PAGE_GUEST_CHANGED; + else + hv->hv_tsc_page_status = HV_TSC_PAGE_HOST_CHANGED; kvm_make_request(KVM_REQ_MASTERCLOCK_UPDATE, vcpu); + } else { + hv->hv_tsc_page_status = HV_TSC_PAGE_UNSET; + } break; case HV_X64_MSR_CRASH_P0 ... HV_X64_MSR_CRASH_P4: return kvm_hv_msr_set_crash_data(kvm, @@ -1229,6 +1297,9 @@ static int kvm_hv_set_msr_pw(struct kvm_vcpu *vcpu, u32 msr, u64 data, hv->hv_tsc_emulation_control = data; break; case HV_X64_MSR_TSC_EMULATION_STATUS: + if (data && !host) + return 1; + hv->hv_tsc_emulation_status = data; break; case HV_X64_MSR_TIME_REF_COUNT: diff --git a/arch/x86/kvm/hyperv.h b/arch/x86/kvm/hyperv.h index e951af1fcb2c..60547d5cb6d7 100644 --- a/arch/x86/kvm/hyperv.h +++ b/arch/x86/kvm/hyperv.h @@ -133,6 +133,7 @@ void kvm_hv_process_stimers(struct kvm_vcpu *vcpu); void kvm_hv_setup_tsc_page(struct kvm *kvm, struct pvclock_vcpu_time_info *hv_clock); +void kvm_hv_invalidate_tsc_page(struct kvm *kvm); void kvm_hv_init_vm(struct kvm *kvm); void kvm_hv_destroy_vm(struct kvm *kvm); diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c index 3d8824e1448f..540d43ba2cf4 100644 --- a/arch/x86/kvm/svm/nested.c +++ b/arch/x86/kvm/svm/nested.c @@ -427,7 +427,6 @@ static void nested_vmcb02_prepare_save(struct vcpu_svm *svm, struct vmcb *vmcb12 nested_vmcb02_compute_g_pat(svm); /* Load the nested guest state */ - if (svm->nested.vmcb12_gpa != svm->nested.last_vmcb12_gpa) { new_vmcb12 = true; svm->nested.last_vmcb12_gpa = svm->nested.vmcb12_gpa; diff --git a/arch/x86/kvm/svm/pmu.c b/arch/x86/kvm/svm/pmu.c index 035da07500e8..fdf587f19c5f 100644 --- a/arch/x86/kvm/svm/pmu.c +++ b/arch/x86/kvm/svm/pmu.c @@ -98,6 +98,8 @@ static enum index msr_to_index(u32 msr) static inline struct kvm_pmc *get_gp_pmc_amd(struct kvm_pmu *pmu, u32 msr, enum pmu_type type) { + struct kvm_vcpu *vcpu = pmu_to_vcpu(pmu); + switch (msr) { case MSR_F15H_PERF_CTL0: case MSR_F15H_PERF_CTL1: @@ -105,6 +107,9 @@ static inline struct kvm_pmc *get_gp_pmc_amd(struct kvm_pmu *pmu, u32 msr, case MSR_F15H_PERF_CTL3: case MSR_F15H_PERF_CTL4: case MSR_F15H_PERF_CTL5: + if (!guest_cpuid_has(vcpu, X86_FEATURE_PERFCTR_CORE)) + return NULL; + fallthrough; case MSR_K7_EVNTSEL0 ... MSR_K7_EVNTSEL3: if (type != PMU_TYPE_EVNTSEL) return NULL; @@ -115,6 +120,9 @@ static inline struct kvm_pmc *get_gp_pmc_amd(struct kvm_pmu *pmu, u32 msr, case MSR_F15H_PERF_CTR3: case MSR_F15H_PERF_CTR4: case MSR_F15H_PERF_CTR5: + if (!guest_cpuid_has(vcpu, X86_FEATURE_PERFCTR_CORE)) + return NULL; + fallthrough; case MSR_K7_PERFCTR0 ... MSR_K7_PERFCTR3: if (type != PMU_TYPE_COUNTER) return NULL; diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c index b4e471b0a231..2632852be856 100644 --- a/arch/x86/kvm/svm/sev.c +++ b/arch/x86/kvm/svm/sev.c @@ -14,6 +14,7 @@ #include <linux/psp-sev.h> #include <linux/pagemap.h> #include <linux/swap.h> +#include <linux/misc_cgroup.h> #include <linux/processor.h> #include <linux/trace_events.h> #include <asm/fpu/internal.h> @@ -28,6 +29,21 @@ #define __ex(x) __kvm_handle_fault_on_reboot(x) +#ifndef CONFIG_KVM_AMD_SEV +/* + * When this config is not defined, SEV feature is not supported and APIs in + * this file are not used but this file still gets compiled into the KVM AMD + * module. + * + * We will not have MISC_CG_RES_SEV and MISC_CG_RES_SEV_ES entries in the enum + * misc_res_type {} defined in linux/misc_cgroup.h. + * + * Below macros allow compilation to succeed. + */ +#define MISC_CG_RES_SEV MISC_CG_RES_TYPES +#define MISC_CG_RES_SEV_ES MISC_CG_RES_TYPES +#endif + static u8 sev_enc_bit; static int sev_flush_asids(void); static DECLARE_RWSEM(sev_deactivate_lock); @@ -93,10 +109,21 @@ static bool __sev_recycle_asids(int min_asid, int max_asid) return true; } -static int sev_asid_new(bool es_active) +static int sev_asid_new(struct kvm_sev_info *sev) { - int pos, min_asid, max_asid; + int pos, min_asid, max_asid, ret; bool retry = true; + enum misc_res_type type; + + type = sev->es_active ? MISC_CG_RES_SEV_ES : MISC_CG_RES_SEV; + WARN_ON(sev->misc_cg); + sev->misc_cg = get_current_misc_cg(); + ret = misc_cg_try_charge(type, sev->misc_cg, 1); + if (ret) { + put_misc_cg(sev->misc_cg); + sev->misc_cg = NULL; + return ret; + } mutex_lock(&sev_bitmap_lock); @@ -104,8 +131,8 @@ static int sev_asid_new(bool es_active) * SEV-enabled guests must use asid from min_sev_asid to max_sev_asid. * SEV-ES-enabled guest can use from 1 to min_sev_asid - 1. */ - min_asid = es_active ? 0 : min_sev_asid - 1; - max_asid = es_active ? min_sev_asid - 1 : max_sev_asid; + min_asid = sev->es_active ? 0 : min_sev_asid - 1; + max_asid = sev->es_active ? min_sev_asid - 1 : max_sev_asid; again: pos = find_next_zero_bit(sev_asid_bitmap, max_sev_asid, min_asid); if (pos >= max_asid) { @@ -114,7 +141,8 @@ again: goto again; } mutex_unlock(&sev_bitmap_lock); - return -EBUSY; + ret = -EBUSY; + goto e_uncharge; } __set_bit(pos, sev_asid_bitmap); @@ -122,6 +150,11 @@ again: mutex_unlock(&sev_bitmap_lock); return pos + 1; +e_uncharge: + misc_cg_uncharge(type, sev->misc_cg, 1); + put_misc_cg(sev->misc_cg); + sev->misc_cg = NULL; + return ret; } static int sev_get_asid(struct kvm *kvm) @@ -131,14 +164,15 @@ static int sev_get_asid(struct kvm *kvm) return sev->asid; } -static void sev_asid_free(int asid) +static void sev_asid_free(struct kvm_sev_info *sev) { struct svm_cpu_data *sd; int cpu, pos; + enum misc_res_type type; mutex_lock(&sev_bitmap_lock); - pos = asid - 1; + pos = sev->asid - 1; __set_bit(pos, sev_reclaim_asid_bitmap); for_each_possible_cpu(cpu) { @@ -147,6 +181,11 @@ static void sev_asid_free(int asid) } mutex_unlock(&sev_bitmap_lock); + + type = sev->es_active ? MISC_CG_RES_SEV_ES : MISC_CG_RES_SEV; + misc_cg_uncharge(type, sev->misc_cg, 1); + put_misc_cg(sev->misc_cg); + sev->misc_cg = NULL; } static void sev_unbind_asid(struct kvm *kvm, unsigned int handle) @@ -182,23 +221,27 @@ static int sev_guest_init(struct kvm *kvm, struct kvm_sev_cmd *argp) if (unlikely(sev->active)) return ret; - asid = sev_asid_new(es_active); + sev->es_active = es_active; + asid = sev_asid_new(sev); if (asid < 0) - return ret; + goto e_no_asid; + sev->asid = asid; ret = sev_platform_init(&argp->error); if (ret) goto e_free; sev->active = true; - sev->es_active = es_active; sev->asid = asid; INIT_LIST_HEAD(&sev->regions_list); return 0; e_free: - sev_asid_free(asid); + sev_asid_free(sev); + sev->asid = 0; +e_no_asid: + sev->es_active = false; return ret; } @@ -1753,12 +1796,12 @@ void sev_vm_destroy(struct kvm *kvm) mutex_unlock(&kvm->lock); sev_unbind_asid(kvm, sev->handle); - sev_asid_free(sev->asid); + sev_asid_free(sev); } void __init sev_hardware_setup(void) { - unsigned int eax, ebx, ecx, edx; + unsigned int eax, ebx, ecx, edx, sev_asid_count, sev_es_asid_count; bool sev_es_supported = false; bool sev_supported = false; @@ -1791,7 +1834,11 @@ void __init sev_hardware_setup(void) if (!sev_reclaim_asid_bitmap) goto out; - pr_info("SEV supported: %u ASIDs\n", max_sev_asid - min_sev_asid + 1); + sev_asid_count = max_sev_asid - min_sev_asid + 1; + if (misc_cg_set_capacity(MISC_CG_RES_SEV, sev_asid_count)) + goto out; + + pr_info("SEV supported: %u ASIDs\n", sev_asid_count); sev_supported = true; /* SEV-ES support requested? */ @@ -1806,7 +1853,11 @@ void __init sev_hardware_setup(void) if (min_sev_asid == 1) goto out; - pr_info("SEV-ES supported: %u ASIDs\n", min_sev_asid - 1); + sev_es_asid_count = min_sev_asid - 1; + if (misc_cg_set_capacity(MISC_CG_RES_SEV_ES, sev_es_asid_count)) + goto out; + + pr_info("SEV-ES supported: %u ASIDs\n", sev_es_asid_count); sev_es_supported = true; out: @@ -1821,6 +1872,8 @@ void sev_hardware_teardown(void) bitmap_free(sev_asid_bitmap); bitmap_free(sev_reclaim_asid_bitmap); + misc_cg_set_capacity(MISC_CG_RES_SEV, 0); + misc_cg_set_capacity(MISC_CG_RES_SEV_ES, 0); sev_flush_asids(); } diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h index 454da1c1d9b7..d6206196eec1 100644 --- a/arch/x86/kvm/svm/svm.h +++ b/arch/x86/kvm/svm/svm.h @@ -69,6 +69,7 @@ struct kvm_sev_info { struct list_head regions_list; /* List of registered regions */ u64 ap_jump_table; /* SEV-ES AP Jump Table address */ struct kvm *enc_context_owner; /* Owner of copied encryption context */ + struct misc_cg *misc_cg; /* For misc cgroup accounting */ }; struct kvm_svm { diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index c9ba6f2d9bcd..f0d0b6e043ae 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -275,8 +275,7 @@ static struct kmem_cache *x86_emulator_cache; * When called, it means the previous get/set msr reached an invalid msr. * Return true if we want to ignore/silent this failed msr access. */ -static bool kvm_msr_ignored_check(struct kvm_vcpu *vcpu, u32 msr, - u64 data, bool write) +static bool kvm_msr_ignored_check(u32 msr, u64 data, bool write) { const char *op = write ? "wrmsr" : "rdmsr"; @@ -1451,7 +1450,7 @@ static int do_get_msr_feature(struct kvm_vcpu *vcpu, unsigned index, u64 *data) if (r == KVM_MSR_RET_INVALID) { /* Unconditionally clear the output for simplicity */ *data = 0; - if (kvm_msr_ignored_check(vcpu, index, 0, false)) + if (kvm_msr_ignored_check(index, 0, false)) r = 0; } @@ -1532,35 +1531,44 @@ EXPORT_SYMBOL_GPL(kvm_enable_efer_bits); bool kvm_msr_allowed(struct kvm_vcpu *vcpu, u32 index, u32 type) { + struct kvm_x86_msr_filter *msr_filter; + struct msr_bitmap_range *ranges; struct kvm *kvm = vcpu->kvm; - struct msr_bitmap_range *ranges = kvm->arch.msr_filter.ranges; - u32 count = kvm->arch.msr_filter.count; - u32 i; - bool r = kvm->arch.msr_filter.default_allow; + bool allowed; int idx; + u32 i; - /* MSR filtering not set up or x2APIC enabled, allow everything */ - if (!count || (index >= 0x800 && index <= 0x8ff)) + /* x2APIC MSRs do not support filtering. */ + if (index >= 0x800 && index <= 0x8ff) return true; - /* Prevent collision with set_msr_filter */ idx = srcu_read_lock(&kvm->srcu); - for (i = 0; i < count; i++) { + msr_filter = srcu_dereference(kvm->arch.msr_filter, &kvm->srcu); + if (!msr_filter) { + allowed = true; + goto out; + } + + allowed = msr_filter->default_allow; + ranges = msr_filter->ranges; + + for (i = 0; i < msr_filter->count; i++) { u32 start = ranges[i].base; u32 end = start + ranges[i].nmsrs; u32 flags = ranges[i].flags; unsigned long *bitmap = ranges[i].bitmap; if ((index >= start) && (index < end) && (flags & type)) { - r = !!test_bit(index - start, bitmap); + allowed = !!test_bit(index - start, bitmap); break; } } +out: srcu_read_unlock(&kvm->srcu, idx); - return r; + return allowed; } EXPORT_SYMBOL_GPL(kvm_msr_allowed); @@ -1617,7 +1625,7 @@ static int kvm_set_msr_ignored_check(struct kvm_vcpu *vcpu, int ret = __kvm_set_msr(vcpu, index, data, host_initiated); if (ret == KVM_MSR_RET_INVALID) - if (kvm_msr_ignored_check(vcpu, index, data, true)) + if (kvm_msr_ignored_check(index, data, true)) ret = 0; return ret; @@ -1655,7 +1663,7 @@ static int kvm_get_msr_ignored_check(struct kvm_vcpu *vcpu, if (ret == KVM_MSR_RET_INVALID) { /* Unconditionally clear *data for simplicity */ *data = 0; - if (kvm_msr_ignored_check(vcpu, index, 0, false)) + if (kvm_msr_ignored_check(index, 0, false)) ret = 0; } @@ -2360,7 +2368,7 @@ static void kvm_synchronize_tsc(struct kvm_vcpu *vcpu, u64 data) kvm_vcpu_write_tsc_offset(vcpu, offset); raw_spin_unlock_irqrestore(&kvm->arch.tsc_write_lock, flags); - spin_lock(&kvm->arch.pvclock_gtod_sync_lock); + spin_lock_irqsave(&kvm->arch.pvclock_gtod_sync_lock, flags); if (!matched) { kvm->arch.nr_vcpus_matched_tsc = 0; } else if (!already_matched) { @@ -2368,7 +2376,7 @@ static void kvm_synchronize_tsc(struct kvm_vcpu *vcpu, u64 data) } kvm_track_tsc_matching(vcpu); - spin_unlock(&kvm->arch.pvclock_gtod_sync_lock); + spin_unlock_irqrestore(&kvm->arch.pvclock_gtod_sync_lock, flags); } static inline void adjust_tsc_offset_guest(struct kvm_vcpu *vcpu, @@ -2590,11 +2598,16 @@ static void kvm_gen_update_masterclock(struct kvm *kvm) int i; struct kvm_vcpu *vcpu; struct kvm_arch *ka = &kvm->arch; + unsigned long flags; + + kvm_hv_invalidate_tsc_page(kvm); - spin_lock(&ka->pvclock_gtod_sync_lock); kvm_make_mclock_inprogress_request(kvm); + /* no guest entries from this point */ + spin_lock_irqsave(&ka->pvclock_gtod_sync_lock, flags); pvclock_update_vm_gtod_copy(kvm); + spin_unlock_irqrestore(&ka->pvclock_gtod_sync_lock, flags); kvm_for_each_vcpu(i, vcpu, kvm) kvm_make_request(KVM_REQ_CLOCK_UPDATE, vcpu); @@ -2602,8 +2615,6 @@ static void kvm_gen_update_masterclock(struct kvm *kvm) /* guest entries allowed */ kvm_for_each_vcpu(i, vcpu, kvm) kvm_clear_request(KVM_REQ_MCLOCK_INPROGRESS, vcpu); - - spin_unlock(&ka->pvclock_gtod_sync_lock); #endif } @@ -2611,17 +2622,18 @@ u64 get_kvmclock_ns(struct kvm *kvm) { struct kvm_arch *ka = &kvm->arch; struct pvclock_vcpu_time_info hv_clock; + unsigned long flags; u64 ret; - spin_lock(&ka->pvclock_gtod_sync_lock); + spin_lock_irqsave(&ka->pvclock_gtod_sync_lock, flags); if (!ka->use_master_clock) { - spin_unlock(&ka->pvclock_gtod_sync_lock); + spin_unlock_irqrestore(&ka->pvclock_gtod_sync_lock, flags); return get_kvmclock_base_ns() + ka->kvmclock_offset; } hv_clock.tsc_timestamp = ka->master_cycle_now; hv_clock.system_time = ka->master_kernel_ns + ka->kvmclock_offset; - spin_unlock(&ka->pvclock_gtod_sync_lock); + spin_unlock_irqrestore(&ka->pvclock_gtod_sync_lock, flags); /* both __this_cpu_read() and rdtsc() should be on the same cpu */ get_cpu(); @@ -2715,13 +2727,13 @@ static int kvm_guest_time_update(struct kvm_vcpu *v) * If the host uses TSC clock, then passthrough TSC as stable * to the guest. */ - spin_lock(&ka->pvclock_gtod_sync_lock); + spin_lock_irqsave(&ka->pvclock_gtod_sync_lock, flags); use_master_clock = ka->use_master_clock; if (use_master_clock) { host_tsc = ka->master_cycle_now; kernel_ns = ka->master_kernel_ns; } - spin_unlock(&ka->pvclock_gtod_sync_lock); + spin_unlock_irqrestore(&ka->pvclock_gtod_sync_lock, flags); /* Keep irq disabled to prevent changes to the clock */ local_irq_save(flags); @@ -5425,25 +5437,34 @@ split_irqchip_unlock: return r; } -static void kvm_clear_msr_filter(struct kvm *kvm) +static struct kvm_x86_msr_filter *kvm_alloc_msr_filter(bool default_allow) +{ + struct kvm_x86_msr_filter *msr_filter; + + msr_filter = kzalloc(sizeof(*msr_filter), GFP_KERNEL_ACCOUNT); + if (!msr_filter) + return NULL; + + msr_filter->default_allow = default_allow; + return msr_filter; +} + +static void kvm_free_msr_filter(struct kvm_x86_msr_filter *msr_filter) { u32 i; - u32 count = kvm->arch.msr_filter.count; - struct msr_bitmap_range ranges[16]; - mutex_lock(&kvm->lock); - kvm->arch.msr_filter.count = 0; - memcpy(ranges, kvm->arch.msr_filter.ranges, count * sizeof(ranges[0])); - mutex_unlock(&kvm->lock); - synchronize_srcu(&kvm->srcu); + if (!msr_filter) + return; - for (i = 0; i < count; i++) - kfree(ranges[i].bitmap); + for (i = 0; i < msr_filter->count; i++) + kfree(msr_filter->ranges[i].bitmap); + + kfree(msr_filter); } -static int kvm_add_msr_filter(struct kvm *kvm, struct kvm_msr_filter_range *user_range) +static int kvm_add_msr_filter(struct kvm_x86_msr_filter *msr_filter, + struct kvm_msr_filter_range *user_range) { - struct msr_bitmap_range *ranges = kvm->arch.msr_filter.ranges; struct msr_bitmap_range range; unsigned long *bitmap = NULL; size_t bitmap_size; @@ -5477,11 +5498,9 @@ static int kvm_add_msr_filter(struct kvm *kvm, struct kvm_msr_filter_range *user goto err; } - /* Everything ok, add this range identifier to our global pool */ - ranges[kvm->arch.msr_filter.count] = range; - /* Make sure we filled the array before we tell anyone to walk it */ - smp_wmb(); - kvm->arch.msr_filter.count++; + /* Everything ok, add this range identifier. */ + msr_filter->ranges[msr_filter->count] = range; + msr_filter->count++; return 0; err: @@ -5492,10 +5511,11 @@ err: static int kvm_vm_ioctl_set_msr_filter(struct kvm *kvm, void __user *argp) { struct kvm_msr_filter __user *user_msr_filter = argp; + struct kvm_x86_msr_filter *new_filter, *old_filter; struct kvm_msr_filter filter; bool default_allow; - int r = 0; bool empty = true; + int r = 0; u32 i; if (copy_from_user(&filter, user_msr_filter, sizeof(filter))) @@ -5508,25 +5528,32 @@ static int kvm_vm_ioctl_set_msr_filter(struct kvm *kvm, void __user *argp) if (empty && !default_allow) return -EINVAL; - kvm_clear_msr_filter(kvm); - - kvm->arch.msr_filter.default_allow = default_allow; + new_filter = kvm_alloc_msr_filter(default_allow); + if (!new_filter) + return -ENOMEM; - /* - * Protect from concurrent calls to this function that could trigger - * a TOCTOU violation on kvm->arch.msr_filter.count. - */ - mutex_lock(&kvm->lock); for (i = 0; i < ARRAY_SIZE(filter.ranges); i++) { - r = kvm_add_msr_filter(kvm, &filter.ranges[i]); - if (r) - break; + r = kvm_add_msr_filter(new_filter, &filter.ranges[i]); + if (r) { + kvm_free_msr_filter(new_filter); + return r; + } } + mutex_lock(&kvm->lock); + + /* The per-VM filter is protected by kvm->lock... */ + old_filter = srcu_dereference_check(kvm->arch.msr_filter, &kvm->srcu, 1); + + rcu_assign_pointer(kvm->arch.msr_filter, new_filter); + synchronize_srcu(&kvm->srcu); + + kvm_free_msr_filter(old_filter); + kvm_make_all_cpus_request(kvm, KVM_REQ_MSR_FILTER_CHANGED); mutex_unlock(&kvm->lock); - return r; + return 0; } long kvm_arch_vm_ioctl(struct file *filp, @@ -5773,6 +5800,7 @@ set_pit2_out: } #endif case KVM_SET_CLOCK: { + struct kvm_arch *ka = &kvm->arch; struct kvm_clock_data user_ns; u64 now_ns; @@ -5791,8 +5819,22 @@ set_pit2_out: * pvclock_update_vm_gtod_copy(). */ kvm_gen_update_masterclock(kvm); - now_ns = get_kvmclock_ns(kvm); - kvm->arch.kvmclock_offset += user_ns.clock - now_ns; + + /* + * This pairs with kvm_guest_time_update(): when masterclock is + * in use, we use master_kernel_ns + kvmclock_offset to set + * unsigned 'system_time' so if we use get_kvmclock_ns() (which + * is slightly ahead) here we risk going negative on unsigned + * 'system_time' when 'user_ns.clock' is very small. + */ + spin_lock_irq(&ka->pvclock_gtod_sync_lock); + if (kvm->arch.use_master_clock) + now_ns = ka->master_kernel_ns; + else + now_ns = get_kvmclock_base_ns(); + ka->kvmclock_offset = user_ns.clock - now_ns; + spin_unlock_irq(&ka->pvclock_gtod_sync_lock); + kvm_make_all_cpus_request(kvm, KVM_REQ_CLOCK_UPDATE); break; } @@ -6678,7 +6720,7 @@ static int kvm_emulate_wbinvd_noskip(struct kvm_vcpu *vcpu) int cpu = get_cpu(); cpumask_set_cpu(cpu, vcpu->arch.wbinvd_dirty_mask); - smp_call_function_many(vcpu->arch.wbinvd_dirty_mask, + on_each_cpu_mask(vcpu->arch.wbinvd_dirty_mask, wbinvd_ipi, NULL, 1); put_cpu(); cpumask_clear(vcpu->arch.wbinvd_dirty_mask); @@ -7773,6 +7815,7 @@ static void kvm_hyperv_tsc_notifier(void) struct kvm *kvm; struct kvm_vcpu *vcpu; int cpu; + unsigned long flags; mutex_lock(&kvm_lock); list_for_each_entry(kvm, &vm_list, vm_list) @@ -7788,17 +7831,15 @@ static void kvm_hyperv_tsc_notifier(void) list_for_each_entry(kvm, &vm_list, vm_list) { struct kvm_arch *ka = &kvm->arch; - spin_lock(&ka->pvclock_gtod_sync_lock); - + spin_lock_irqsave(&ka->pvclock_gtod_sync_lock, flags); pvclock_update_vm_gtod_copy(kvm); + spin_unlock_irqrestore(&ka->pvclock_gtod_sync_lock, flags); kvm_for_each_vcpu(cpu, vcpu, kvm) kvm_make_request(KVM_REQ_CLOCK_UPDATE, vcpu); kvm_for_each_vcpu(cpu, vcpu, kvm) kvm_clear_request(KVM_REQ_MCLOCK_INPROGRESS, vcpu); - - spin_unlock(&ka->pvclock_gtod_sync_lock); } mutex_unlock(&kvm_lock); } @@ -10745,8 +10786,6 @@ void kvm_arch_pre_destroy_vm(struct kvm *kvm) void kvm_arch_destroy_vm(struct kvm *kvm) { - u32 i; - if (current->mm == kvm->mm) { /* * Free memory regions allocated on behalf of userspace, @@ -10762,8 +10801,7 @@ void kvm_arch_destroy_vm(struct kvm *kvm) mutex_unlock(&kvm->slots_lock); } static_call_cond(kvm_x86_vm_destroy)(kvm); - for (i = 0; i < kvm->arch.msr_filter.count; i++) - kfree(kvm->arch.msr_filter.ranges[i].bitmap); + kvm_free_msr_filter(srcu_dereference_check(kvm->arch.msr_filter, &kvm->srcu, 1)); kvm_pic_destroy(kvm); kvm_ioapic_destroy(kvm); kvm_free_vcpus(kvm); diff --git a/arch/x86/kvm/x86.h b/arch/x86/kvm/x86.h index daccf20fbcd5..5334bf43fdb8 100644 --- a/arch/x86/kvm/x86.h +++ b/arch/x86/kvm/x86.h @@ -260,7 +260,6 @@ static inline bool kvm_vcpu_latch_init(struct kvm_vcpu *vcpu) void kvm_write_wall_clock(struct kvm *kvm, gpa_t wall_clock, int sec_hi_ofs); void kvm_inject_realmode_interrupt(struct kvm_vcpu *vcpu, int irq, int inc_eip); -void kvm_write_tsc(struct kvm_vcpu *vcpu, struct msr_data *msr); u64 get_kvmclock_ns(struct kvm *kvm); int kvm_read_guest_virt(struct kvm_vcpu *vcpu, |