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Diffstat (limited to 'arch/x86/kvm/svm.c')
-rw-r--r--arch/x86/kvm/svm.c80
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;
}