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-rw-r--r--arch/x86/include/asm/kvm_host.h2
-rw-r--r--arch/x86/kvm/svm/nested.c15
-rw-r--r--arch/x86/kvm/svm/svm.c29
-rw-r--r--arch/x86/kvm/vmx/vmx.c5
-rw-r--r--arch/x86/kvm/x86.c11
5 files changed, 32 insertions, 30 deletions
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index de0c28814348..9e8263b1e6fe 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1093,7 +1093,6 @@ struct kvm_x86_ops {
void (*set_idt)(struct kvm_vcpu *vcpu, struct desc_ptr *dt);
void (*get_gdt)(struct kvm_vcpu *vcpu, struct desc_ptr *dt);
void (*set_gdt)(struct kvm_vcpu *vcpu, struct desc_ptr *dt);
- void (*set_dr6)(struct kvm_vcpu *vcpu, unsigned long value);
void (*sync_dirty_debug_regs)(struct kvm_vcpu *vcpu);
void (*set_dr7)(struct kvm_vcpu *vcpu, unsigned long value);
void (*cache_reg)(struct kvm_vcpu *vcpu, enum kvm_reg reg);
@@ -1623,7 +1622,6 @@ int kvm_pv_send_ipi(struct kvm *kvm, unsigned long ipi_bitmap_low,
void kvm_define_shared_msr(unsigned index, u32 msr);
int kvm_set_shared_msr(unsigned index, u64 val, u64 mask);
-void kvm_update_dr6(struct kvm_vcpu *vcpu);
u64 kvm_scale_tsc(struct kvm_vcpu *vcpu, u64 tsc);
u64 kvm_read_l1_tsc(struct kvm_vcpu *vcpu, u64 host_tsc);
diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c
index 9cfa8098995e..9a2a62e5afeb 100644
--- a/arch/x86/kvm/svm/nested.c
+++ b/arch/x86/kvm/svm/nested.c
@@ -269,7 +269,6 @@ void enter_svm_guest_mode(struct vcpu_svm *svm, u64 vmcb_gpa,
svm->vmcb->save.rip = nested_vmcb->save.rip;
svm->vmcb->save.dr7 = nested_vmcb->save.dr7;
svm->vcpu.arch.dr6 = nested_vmcb->save.dr6;
- kvm_update_dr6(&svm->vcpu);
svm->vmcb->save.cpl = nested_vmcb->save.cpl;
svm->nested.vmcb_msrpm = nested_vmcb->control.msrpm_base_pa & ~0x0fffULL;
@@ -634,10 +633,18 @@ static int nested_svm_intercept_db(struct vcpu_svm *svm)
reflected_db:
/*
- * Synchronize guest DR6 here just like in db_interception; it will
- * be moved into the nested VMCB by nested_svm_vmexit.
+ * Synchronize guest DR6 here just like in kvm_deliver_exception_payload;
+ * it will be moved into the nested VMCB by nested_svm_vmexit. Once
+ * exceptions will be moved to svm_check_nested_events, all this stuff
+ * will just go away and we could just return NESTED_EXIT_HOST
+ * unconditionally. db_interception will queue the exception, which
+ * will be processed by svm_check_nested_events if a nested vmexit is
+ * required, and we will just use kvm_deliver_exception_payload to copy
+ * the payload to DR6 before vmexit.
*/
- svm->vcpu.arch.dr6 = dr6;
+ WARN_ON(svm->vcpu.arch.switch_db_regs & KVM_DEBUGREG_WONT_EXIT);
+ svm->vcpu.arch.dr6 &= ~(DR_TRAP_BITS | DR6_RTM);
+ svm->vcpu.arch.dr6 |= dr6 & ~DR6_FIXED_1;
return NESTED_EXIT_DONE;
}
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index f03bffafd9e6..a862c768fd54 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -1672,12 +1672,14 @@ static void new_asid(struct vcpu_svm *svm, struct svm_cpu_data *sd)
mark_dirty(svm->vmcb, VMCB_ASID);
}
-static void svm_set_dr6(struct kvm_vcpu *vcpu, unsigned long value)
+static void svm_set_dr6(struct vcpu_svm *svm, unsigned long value)
{
- struct vcpu_svm *svm = to_svm(vcpu);
+ struct vmcb *vmcb = svm->vmcb;
- svm->vmcb->save.dr6 = value;
- mark_dirty(svm->vmcb, VMCB_DR);
+ if (unlikely(value != vmcb->save.dr6)) {
+ vmcb->save.dr6 = value;
+ mark_dirty(vmcb, VMCB_DR);
+ }
}
static void svm_sync_dirty_debug_regs(struct kvm_vcpu *vcpu)
@@ -1688,9 +1690,12 @@ static void svm_sync_dirty_debug_regs(struct kvm_vcpu *vcpu)
get_debugreg(vcpu->arch.db[1], 1);
get_debugreg(vcpu->arch.db[2], 2);
get_debugreg(vcpu->arch.db[3], 3);
+ /*
+ * We cannot reset svm->vmcb->save.dr6 to DR6_FIXED_1|DR6_RTM here,
+ * because db_interception might need it. We can do it before vmentry.
+ */
vcpu->arch.dr6 = svm->vmcb->save.dr6;
vcpu->arch.dr7 = svm->vmcb->save.dr7;
-
vcpu->arch.switch_db_regs &= ~KVM_DEBUGREG_WONT_EXIT;
set_dr_intercepts(svm);
}
@@ -1734,8 +1739,8 @@ static int db_interception(struct vcpu_svm *svm)
if (!(svm->vcpu.guest_debug &
(KVM_GUESTDBG_SINGLESTEP | KVM_GUESTDBG_USE_HW_BP)) &&
!svm->nmi_singlestep) {
- vcpu->arch.dr6 = svm->vmcb->save.dr6;
- kvm_queue_exception(&svm->vcpu, DB_VECTOR);
+ u32 payload = (svm->vmcb->save.dr6 ^ DR6_RTM) & ~DR6_FIXED_1;
+ kvm_queue_exception_p(&svm->vcpu, DB_VECTOR, payload);
return 1;
}
@@ -3313,6 +3318,15 @@ static void svm_vcpu_run(struct kvm_vcpu *vcpu)
svm->vmcb->save.cr2 = vcpu->arch.cr2;
+ /*
+ * Run with all-zero DR6 unless needed, so that we can get the exact cause
+ * of a #DB.
+ */
+ if (unlikely(svm->vcpu.arch.switch_db_regs & KVM_DEBUGREG_WONT_EXIT))
+ svm_set_dr6(svm, vcpu->arch.dr6);
+ else
+ svm_set_dr6(svm, DR6_FIXED_1 | DR6_RTM);
+
clgi();
kvm_load_guest_xsave_state(vcpu);
@@ -3927,7 +3941,6 @@ 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,
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 6153a47109d3..e2b71b0cdfce 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -4965,10 +4965,6 @@ static int handle_dr(struct kvm_vcpu *vcpu)
return kvm_skip_emulated_instruction(vcpu);
}
-static void vmx_set_dr6(struct kvm_vcpu *vcpu, unsigned long val)
-{
-}
-
static void vmx_sync_dirty_debug_regs(struct kvm_vcpu *vcpu)
{
get_debugreg(vcpu->arch.db[0], 0);
@@ -7731,7 +7727,6 @@ static struct kvm_x86_ops vmx_x86_ops __initdata = {
.set_idt = vmx_set_idt,
.get_gdt = vmx_get_gdt,
.set_gdt = vmx_set_gdt,
- .set_dr6 = vmx_set_dr6,
.set_dr7 = vmx_set_dr7,
.sync_dirty_debug_regs = vmx_sync_dirty_debug_regs,
.cache_reg = vmx_cache_reg,
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 4ea644827b8a..f780af601c5f 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -473,7 +473,6 @@ void kvm_deliver_exception_payload(struct kvm_vcpu *vcpu)
* breakpoint), it is reserved and must be zero in DR6.
*/
vcpu->arch.dr6 &= ~BIT(12);
- kvm_update_dr6(vcpu);
break;
case PF_VECTOR:
vcpu->arch.cr2 = payload;
@@ -1047,12 +1046,6 @@ static void kvm_update_dr0123(struct kvm_vcpu *vcpu)
}
}
-void kvm_update_dr6(struct kvm_vcpu *vcpu)
-{
- if (!(vcpu->guest_debug & KVM_GUESTDBG_USE_HW_BP))
- kvm_x86_ops.set_dr6(vcpu, vcpu->arch.dr6);
-}
-
static void kvm_update_dr7(struct kvm_vcpu *vcpu)
{
unsigned long dr7;
@@ -1092,7 +1085,6 @@ static int __kvm_set_dr(struct kvm_vcpu *vcpu, int dr, unsigned long val)
if (val & 0xffffffff00000000ULL)
return -1; /* #GP */
vcpu->arch.dr6 = (val & DR6_VOLATILE) | kvm_dr6_fixed(vcpu);
- kvm_update_dr6(vcpu);
break;
case 5:
/* fall through */
@@ -4008,7 +4000,6 @@ static int kvm_vcpu_ioctl_x86_set_debugregs(struct kvm_vcpu *vcpu,
memcpy(vcpu->arch.db, dbgregs->db, sizeof(vcpu->arch.db));
kvm_update_dr0123(vcpu);
vcpu->arch.dr6 = dbgregs->dr6;
- kvm_update_dr6(vcpu);
vcpu->arch.dr7 = dbgregs->dr7;
kvm_update_dr7(vcpu);
@@ -8417,7 +8408,6 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu)
WARN_ON(vcpu->guest_debug & KVM_GUESTDBG_USE_HW_BP);
kvm_x86_ops.sync_dirty_debug_regs(vcpu);
kvm_update_dr0123(vcpu);
- kvm_update_dr6(vcpu);
kvm_update_dr7(vcpu);
vcpu->arch.switch_db_regs &= ~KVM_DEBUGREG_RELOAD;
}
@@ -9478,7 +9468,6 @@ void kvm_vcpu_reset(struct kvm_vcpu *vcpu, bool init_event)
memset(vcpu->arch.db, 0, sizeof(vcpu->arch.db));
kvm_update_dr0123(vcpu);
vcpu->arch.dr6 = DR6_INIT;
- kvm_update_dr6(vcpu);
vcpu->arch.dr7 = DR7_FIXED_1;
kvm_update_dr7(vcpu);
generated by cgit v1.2.3 (git 2.25.1) at 2024-08-28 06:59:25 +0000