summaryrefslogtreecommitdiff
path: root/arch/x86/kvm/svm/svm.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/x86/kvm/svm/svm.c')
-rw-r--r--arch/x86/kvm/svm/svm.c27
1 files changed, 19 insertions, 8 deletions
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index a96facc05139..b6bbd0dc4e65 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -1426,7 +1426,7 @@ static void svm_clear_current_vmcb(struct vmcb *vmcb)
{
int i;
- for_each_online_cpu(i)
+ for_each_possible_cpu(i)
cmpxchg(per_cpu_ptr(&svm_data.current_vmcb, i), vmcb, NULL);
}
@@ -1920,11 +1920,11 @@ static void new_asid(struct vcpu_svm *svm, struct svm_cpu_data *sd)
svm->asid = sd->next_asid++;
}
-static void svm_set_dr6(struct vcpu_svm *svm, unsigned long value)
+static void svm_set_dr6(struct kvm_vcpu *vcpu, unsigned long value)
{
- struct vmcb *vmcb = svm->vmcb;
+ struct vmcb *vmcb = to_svm(vcpu)->vmcb;
- if (svm->vcpu.arch.guest_state_protected)
+ if (vcpu->arch.guest_state_protected)
return;
if (unlikely(value != vmcb->save.dr6)) {
@@ -3039,6 +3039,18 @@ static int svm_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr)
__func__, data);
break;
}
+
+ /*
+ * AMD changed the architectural behavior of bits 5:2. On CPUs
+ * without BusLockTrap, bits 5:2 control "external pins", but
+ * on CPUs that support BusLockDetect, bit 2 enables BusLockTrap
+ * and bits 5:3 are reserved-to-zero. Sadly, old KVM allowed
+ * the guest to set bits 5:2 despite not actually virtualizing
+ * Performance-Monitoring/Breakpoint external pins. Drop bits
+ * 5:2 for backwards compatibility.
+ */
+ data &= ~GENMASK(5, 2);
+
if (data & DEBUGCTL_RESERVED_BITS)
return 1;
@@ -4023,10 +4035,8 @@ static __no_kcsan fastpath_t svm_vcpu_run(struct kvm_vcpu *vcpu)
* Run with all-zero DR6 unless needed, so that we can get the exact cause
* of a #DB.
*/
- if (unlikely(vcpu->arch.switch_db_regs & KVM_DEBUGREG_WONT_EXIT))
- svm_set_dr6(svm, vcpu->arch.dr6);
- else
- svm_set_dr6(svm, DR6_ACTIVE_LOW);
+ if (likely(!(vcpu->arch.switch_db_regs & KVM_DEBUGREG_WONT_EXIT)))
+ svm_set_dr6(vcpu, DR6_ACTIVE_LOW);
clgi();
kvm_load_guest_xsave_state(vcpu);
@@ -4795,6 +4805,7 @@ static struct kvm_x86_ops svm_x86_ops __initdata = {
.set_idt = svm_set_idt,
.get_gdt = svm_get_gdt,
.set_gdt = svm_set_gdt,
+ .set_dr6 = svm_set_dr6,
.set_dr7 = svm_set_dr7,
.sync_dirty_debug_regs = svm_sync_dirty_debug_regs,
.cache_reg = svm_cache_reg,