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
}
-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)
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;
*/
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;
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);
__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;
.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 = {