From: Paolo Bonzini <pbonzini@redhat.com>
To: linux-kernel@vger.kernel.org, kvm@vger.kernel.org
Cc: peterx@redhat.com, Sean Christopherson <sean.j.christopherson@intel.com>
Subject: [PATCH 7/9] KVM: x86: simplify dr6 accessors in kvm_x86_ops
Date: Wed, 6 May 2020 07:10:32 -0400 [thread overview]
Message-ID: <20200506111034.11756-8-pbonzini@redhat.com> (raw)
In-Reply-To: <20200506111034.11756-1-pbonzini@redhat.com>
kvm_x86_ops.set_dr6 is only ever called with vcpu->arch.dr6 as the
second argument, and for both SVM and VMX the VMCB value is kept
synchronized with vcpu->arch.dr6 on #DB; we can therefore remove the
read accessor.
For the write accessor we can avoid the retpoline penalty on Intel
by accepting a NULL value and just skipping the call in that case.
Suggested-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
arch/x86/include/asm/kvm_host.h | 1 -
arch/x86/kvm/svm/svm.c | 6 ------
arch/x86/kvm/vmx/vmx.c | 11 -----------
arch/x86/kvm/x86.c | 8 +++-----
4 files changed, 3 insertions(+), 23 deletions(-)
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 8c247bcb037e..93f6f696d059 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);
- u64 (*get_dr6)(struct kvm_vcpu *vcpu);
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);
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index 5627004e077e..f03bffafd9e6 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -1672,11 +1672,6 @@ static void new_asid(struct vcpu_svm *svm, struct svm_cpu_data *sd)
mark_dirty(svm->vmcb, VMCB_ASID);
}
-static u64 svm_get_dr6(struct kvm_vcpu *vcpu)
-{
- return vcpu->arch.dr6;
-}
-
static void svm_set_dr6(struct kvm_vcpu *vcpu, unsigned long value)
{
struct vcpu_svm *svm = to_svm(vcpu);
@@ -3932,7 +3927,6 @@ static struct kvm_x86_ops svm_x86_ops __initdata = {
.set_idt = svm_set_idt,
.get_gdt = svm_get_gdt,
.set_gdt = svm_set_gdt,
- .get_dr6 = svm_get_dr6,
.set_dr6 = svm_set_dr6,
.set_dr7 = svm_set_dr7,
.sync_dirty_debug_regs = svm_sync_dirty_debug_regs,
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 2384a2dbec44..e2b71b0cdfce 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -4965,15 +4965,6 @@ static int handle_dr(struct kvm_vcpu *vcpu)
return kvm_skip_emulated_instruction(vcpu);
}
-static u64 vmx_get_dr6(struct kvm_vcpu *vcpu)
-{
- return vcpu->arch.dr6;
-}
-
-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);
@@ -7736,8 +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,
- .get_dr6 = vmx_get_dr6,
- .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 f7628555f036..f4254d716b10 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -1050,7 +1050,8 @@ static void kvm_update_dr0123(struct kvm_vcpu *vcpu)
static void kvm_update_dr6(struct kvm_vcpu *vcpu)
{
- if (!(vcpu->guest_debug & KVM_GUESTDBG_USE_HW_BP))
+ if (!(vcpu->guest_debug & KVM_GUESTDBG_USE_HW_BP) &&
+ kvm_x86_ops.set_dr6)
kvm_x86_ops.set_dr6(vcpu, vcpu->arch.dr6);
}
@@ -1129,10 +1130,7 @@ int kvm_get_dr(struct kvm_vcpu *vcpu, int dr, unsigned long *val)
case 4:
/* fall through */
case 6:
- if (vcpu->guest_debug & KVM_GUESTDBG_USE_HW_BP)
- *val = vcpu->arch.dr6;
- else
- *val = kvm_x86_ops.get_dr6(vcpu);
+ *val = vcpu->arch.dr6;
break;
case 5:
/* fall through */
--
2.18.2
next prev parent reply other threads:[~2020-05-06 11:11 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-06 11:10 [PATCH 0/9] KVM_SET_GUEST_DEBUG tests and fixes, DR accessors cleanups Paolo Bonzini
2020-05-06 11:10 ` [PATCH 1/9] KVM: X86: Declare KVM_CAP_SET_GUEST_DEBUG properly Paolo Bonzini
2020-05-06 11:10 ` [PATCH 2/9] KVM: x86: fix DR6 delivery for various cases of #DB injection Paolo Bonzini
2020-05-06 16:01 ` Peter Xu
2020-05-06 11:10 ` [PATCH 3/9] KVM: X86: Set RTM for DB_VECTOR too for KVM_EXIT_DEBUG Paolo Bonzini
2020-05-06 11:10 ` [PATCH 4/9] KVM: X86: Fix single-step with KVM_SET_GUEST_DEBUG Paolo Bonzini
2020-05-06 11:10 ` [PATCH 5/9] KVM: selftests: Add KVM_SET_GUEST_DEBUG test Paolo Bonzini
2020-05-06 11:10 ` [PATCH 6/9] KVM: SVM: keep DR6 synchronized with vcpu->arch.dr6 Paolo Bonzini
2020-05-06 16:04 ` Peter Xu
2020-05-06 11:10 ` Paolo Bonzini [this message]
2020-05-06 16:06 ` [PATCH 7/9] KVM: x86: simplify dr6 accessors in kvm_x86_ops Peter Xu
2020-05-06 16:09 ` Paolo Bonzini
2020-05-06 17:52 ` Peter Xu
2020-05-06 11:10 ` [PATCH 8/9] KVM: x86, SVM: do not clobber guest DR6 on KVM_EXIT_DEBUG Paolo Bonzini
2020-05-06 18:15 ` Peter Xu
2020-05-06 20:07 ` Paolo Bonzini
2020-05-06 21:13 ` Peter Xu
2020-05-06 21:20 ` Sean Christopherson
2020-05-06 23:33 ` Peter Xu
2020-05-06 23:47 ` Sean Christopherson
2020-05-06 11:10 ` [PATCH 9/9] KVM: VMX: pass correct DR6 for GD userspace exit Paolo Bonzini
2020-05-06 17:50 ` Peter Xu
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