diff options
| -rw-r--r-- | arch/x86/kvm/svm.c | 80 |
1 files changed, 71 insertions, 9 deletions
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index a079550d3886..45a287e51e18 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -93,6 +93,9 @@ struct nested_state { }; +#define MSRPM_OFFSETS 16 +static u32 msrpm_offsets[MSRPM_OFFSETS] __read_mostly; + struct vcpu_svm { struct kvm_vcpu vcpu; struct vmcb *vmcb; @@ -510,6 +513,49 @@ static void svm_vcpu_init_msrpm(u32 *msrpm) } } +static void add_msr_offset(u32 offset) +{ + int i; + + for (i = 0; i < MSRPM_OFFSETS; ++i) { + + /* Offset already in list? */ + if (msrpm_offsets[i] == offset) + return; + + /* Slot used by another offset? */ + if (msrpm_offsets[i] != MSR_INVALID) + continue; + + /* Add offset to list */ + msrpm_offsets[i] = offset; + + return; + } + + /* + * If this BUG triggers the msrpm_offsets table has an overflow. Just + * increase MSRPM_OFFSETS in this case. + */ + BUG(); +} + +static void init_msrpm_offsets(void) +{ + int i; + + memset(msrpm_offsets, 0xff, sizeof(msrpm_offsets)); + + for (i = 0; direct_access_msrs[i].index != MSR_INVALID; i++) { + u32 offset; + + offset = svm_msrpm_offset(direct_access_msrs[i].index); + BUG_ON(offset == MSR_INVALID); + + add_msr_offset(offset); + } +} + static void svm_enable_lbrv(struct vcpu_svm *svm) { u32 *msrpm = svm->msrpm; @@ -548,6 +594,8 @@ static __init int svm_hardware_setup(void) memset(iopm_va, 0xff, PAGE_SIZE * (1 << IOPM_ALLOC_ORDER)); iopm_base = page_to_pfn(iopm_pages) << PAGE_SHIFT; + init_msrpm_offsets(); + if (boot_cpu_has(X86_FEATURE_NX)) kvm_enable_efer_bits(EFER_NX); @@ -811,6 +859,7 @@ static struct kvm_vcpu *svm_create_vcpu(struct kvm *kvm, unsigned int id) svm_vcpu_init_msrpm(svm->msrpm); svm->nested.msrpm = page_address(nested_msrpm_pages); + svm_vcpu_init_msrpm(svm->nested.msrpm); svm->vmcb = page_address(page); clear_page(svm->vmcb); @@ -1888,20 +1937,33 @@ static int nested_svm_vmexit(struct vcpu_svm *svm) static bool nested_svm_vmrun_msrpm(struct vcpu_svm *svm) { - u32 *nested_msrpm; - struct page *page; + /* + * This function merges the msr permission bitmaps of kvm and the + * nested vmcb. It is omptimized in that it only merges the parts where + * the kvm msr permission bitmap may contain zero bits + */ int i; - nested_msrpm = nested_svm_map(svm, svm->nested.vmcb_msrpm, &page); - if (!nested_msrpm) - return false; + if (!(svm->nested.intercept & (1ULL << INTERCEPT_MSR_PROT))) + return true; - for (i = 0; i < PAGE_SIZE * (1 << MSRPM_ALLOC_ORDER) / 4; i++) - svm->nested.msrpm[i] = svm->msrpm[i] | nested_msrpm[i]; + for (i = 0; i < MSRPM_OFFSETS; i++) { + u32 value, p; + u64 offset; - svm->vmcb->control.msrpm_base_pa = __pa(svm->nested.msrpm); + if (msrpm_offsets[i] == 0xffffffff) + break; - nested_svm_unmap(page); + offset = svm->nested.vmcb_msrpm + msrpm_offsets[i]; + p = msrpm_offsets[i] / 4; + + if (kvm_read_guest(svm->vcpu.kvm, offset, &value, 4)) + return false; + + svm->nested.msrpm[p] = svm->msrpm[p] | value; + } + + svm->vmcb->control.msrpm_base_pa = __pa(svm->nested.msrpm); return true; } |