diff options
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/kvm/svm/svm.c | 77 | ||||
| -rw-r--r-- | arch/x86/kvm/svm/svm.h | 7 |
2 files changed, 76 insertions, 8 deletions
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index bfb3330cd580..4f401fc6a05d 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -91,7 +91,7 @@ static DEFINE_PER_CPU(u64, current_tsc_ratio); static const struct svm_direct_access_msrs { u32 index; /* Index of the MSR */ bool always; /* True if intercept is always on */ -} direct_access_msrs[] = { +} direct_access_msrs[MAX_DIRECT_ACCESS_MSRS] = { { .index = MSR_STAR, .always = true }, { .index = MSR_IA32_SYSENTER_CS, .always = true }, #ifdef CONFIG_X86_64 @@ -553,15 +553,41 @@ free_cpu_data: } -static bool valid_msr_intercept(u32 index) +static int direct_access_msr_slot(u32 msr) { - int i; + u32 i; for (i = 0; direct_access_msrs[i].index != MSR_INVALID; i++) - if (direct_access_msrs[i].index == index) - return true; + if (direct_access_msrs[i].index == msr) + return i; - return false; + return -ENOENT; +} + +static void set_shadow_msr_intercept(struct kvm_vcpu *vcpu, u32 msr, int read, + int write) +{ + struct vcpu_svm *svm = to_svm(vcpu); + int slot = direct_access_msr_slot(msr); + + if (slot == -ENOENT) + return; + + /* Set the shadow bitmaps to the desired intercept states */ + if (read) + set_bit(slot, svm->shadow_msr_intercept.read); + else + clear_bit(slot, svm->shadow_msr_intercept.read); + + if (write) + set_bit(slot, svm->shadow_msr_intercept.write); + else + clear_bit(slot, svm->shadow_msr_intercept.write); +} + +static bool valid_msr_intercept(u32 index) +{ + return direct_access_msr_slot(index) != -ENOENT; } static bool msr_write_intercepted(struct kvm_vcpu *vcpu, u32 msr) @@ -583,8 +609,8 @@ static bool msr_write_intercepted(struct kvm_vcpu *vcpu, u32 msr) return !!test_bit(bit_write, &tmp); } -static void set_msr_interception(struct kvm_vcpu *vcpu, u32 *msrpm, u32 msr, - int read, int write) +static void set_msr_interception_bitmap(struct kvm_vcpu *vcpu, u32 *msrpm, + u32 msr, int read, int write) { u8 bit_read, bit_write; unsigned long tmp; @@ -596,6 +622,13 @@ static void set_msr_interception(struct kvm_vcpu *vcpu, u32 *msrpm, u32 msr, */ WARN_ON(!valid_msr_intercept(msr)); + /* Enforce non allowed MSRs to trap */ + if (read && !kvm_msr_allowed(vcpu, msr, KVM_MSR_FILTER_READ)) + read = 0; + + if (write && !kvm_msr_allowed(vcpu, msr, KVM_MSR_FILTER_WRITE)) + write = 0; + offset = svm_msrpm_offset(msr); bit_read = 2 * (msr & 0x0f); bit_write = 2 * (msr & 0x0f) + 1; @@ -609,6 +642,13 @@ static void set_msr_interception(struct kvm_vcpu *vcpu, u32 *msrpm, u32 msr, msrpm[offset] = tmp; } +static void set_msr_interception(struct kvm_vcpu *vcpu, u32 *msrpm, u32 msr, + int read, int write) +{ + set_shadow_msr_intercept(vcpu, msr, read, write); + set_msr_interception_bitmap(vcpu, msrpm, msr, read, write); +} + static u32 *svm_vcpu_alloc_msrpm(void) { struct page *pages = alloc_pages(GFP_KERNEL_ACCOUNT, MSRPM_ALLOC_ORDER); @@ -639,6 +679,25 @@ static void svm_vcpu_free_msrpm(u32 *msrpm) __free_pages(virt_to_page(msrpm), MSRPM_ALLOC_ORDER); } +static void svm_msr_filter_changed(struct kvm_vcpu *vcpu) +{ + struct vcpu_svm *svm = to_svm(vcpu); + u32 i; + + /* + * Set intercept permissions for all direct access MSRs again. They + * will automatically get filtered through the MSR filter, so we are + * back in sync after this. + */ + for (i = 0; direct_access_msrs[i].index != MSR_INVALID; i++) { + u32 msr = direct_access_msrs[i].index; + u32 read = test_bit(i, svm->shadow_msr_intercept.read); + u32 write = test_bit(i, svm->shadow_msr_intercept.write); + + set_msr_interception_bitmap(vcpu, svm->msrpm, msr, read, write); + } +} + static void add_msr_offset(u32 offset) { int i; @@ -4222,6 +4281,8 @@ static struct kvm_x86_ops svm_x86_ops __initdata = { .can_emulate_instruction = svm_can_emulate_instruction, .apic_init_signal_blocked = svm_apic_init_signal_blocked, + + .msr_filter_changed = svm_msr_filter_changed, }; static struct kvm_x86_init_ops svm_init_ops __initdata = { diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h index bb3bbc87d3ff..a7f997459b87 100644 --- a/arch/x86/kvm/svm/svm.h +++ b/arch/x86/kvm/svm/svm.h @@ -31,6 +31,7 @@ static const u32 host_save_user_msrs[] = { #define NR_HOST_SAVE_USER_MSRS ARRAY_SIZE(host_save_user_msrs) +#define MAX_DIRECT_ACCESS_MSRS 15 #define MSRPM_OFFSETS 16 extern u32 msrpm_offsets[MSRPM_OFFSETS] __read_mostly; extern bool npt_enabled; @@ -157,6 +158,12 @@ struct vcpu_svm { */ struct list_head ir_list; spinlock_t ir_list_lock; + + /* Save desired MSR intercept (read: pass-through) state */ + struct { + DECLARE_BITMAP(read, MAX_DIRECT_ACCESS_MSRS); + DECLARE_BITMAP(write, MAX_DIRECT_ACCESS_MSRS); + } shadow_msr_intercept; }; struct svm_cpu_data { |