2019-11-04 23:03:02

by Andrea Arcangeli

Subject: [PATCH 10/13] KVM: x86: optimize more exit handlers in vmx.c

Eliminate wasteful call/ret non RETPOLINE case and unnecessary fentry
dynamic tracing hooking points.

Signed-off-by: Andrea Arcangeli <[email protected]>
---
arch/x86/kvm/vmx/vmx.c | 30 +++++-------------------------
1 file changed, 5 insertions(+), 25 deletions(-)

diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 222467b2040e..a6afa5f4a01c 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -4694,7 +4694,7 @@ static int handle_exception_nmi(struct kvm_vcpu *vcpu)
return 0;
}

-static int handle_external_interrupt(struct kvm_vcpu *vcpu)
+static __always_inline int handle_external_interrupt(struct kvm_vcpu *vcpu)
{
++vcpu->stat.irq_exits;
return 1;
@@ -4965,21 +4965,6 @@ void kvm_x86_set_dr7(struct kvm_vcpu *vcpu, unsigned long val)
vmcs_writel(GUEST_DR7, val);
}

-static int handle_cpuid(struct kvm_vcpu *vcpu)
-{
- return kvm_emulate_cpuid(vcpu);
-}
-
-static int handle_rdmsr(struct kvm_vcpu *vcpu)
-{
- return kvm_emulate_rdmsr(vcpu);
-}
-
-static int handle_wrmsr(struct kvm_vcpu *vcpu)
-{
- return kvm_emulate_wrmsr(vcpu);
-}
-
static int handle_tpr_below_threshold(struct kvm_vcpu *vcpu)
{
kvm_apic_update_ppr(vcpu);
@@ -4996,11 +4981,6 @@ static int handle_interrupt_window(struct kvm_vcpu *vcpu)
return 1;
}

-static int handle_halt(struct kvm_vcpu *vcpu)
-{
- return kvm_emulate_halt(vcpu);
-}
-
static int handle_vmcall(struct kvm_vcpu *vcpu)
{
return kvm_emulate_hypercall(vcpu);
@@ -5548,11 +5528,11 @@ static int (*kvm_vmx_exit_handlers[])(struct kvm_vcpu *vcpu) = {
[EXIT_REASON_IO_INSTRUCTION] = handle_io,
[EXIT_REASON_CR_ACCESS] = handle_cr,
[EXIT_REASON_DR_ACCESS] = handle_dr,
- [EXIT_REASON_CPUID] = handle_cpuid,
- [EXIT_REASON_MSR_READ] = handle_rdmsr,
- [EXIT_REASON_MSR_WRITE] = handle_wrmsr,
+ [EXIT_REASON_CPUID] = kvm_emulate_cpuid,
+ [EXIT_REASON_MSR_READ] = kvm_emulate_rdmsr,
+ [EXIT_REASON_MSR_WRITE] = kvm_emulate_wrmsr,
[EXIT_REASON_PENDING_INTERRUPT] = handle_interrupt_window,
- [EXIT_REASON_HLT] = handle_halt,
+ [EXIT_REASON_HLT] = kvm_emulate_halt,
[EXIT_REASON_INVD] = handle_invd,
[EXIT_REASON_INVLPG] = handle_invlpg,
[EXIT_REASON_RDPMC] = handle_rdpmc,

2019-11-05 10:25:58

by Paolo Bonzini

Subject: Re: [PATCH 10/13] KVM: x86: optimize more exit handlers in vmx.c

On 04/11/19 23:59, Andrea Arcangeli wrote:
> Eliminate wasteful call/ret non RETPOLINE case and unnecessary fentry
> dynamic tracing hooking points.
>
> Signed-off-by: Andrea Arcangeli <[email protected]>
> ---
> arch/x86/kvm/vmx/vmx.c | 30 +++++-------------------------
> 1 file changed, 5 insertions(+), 25 deletions(-)
>
> diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
> index 222467b2040e..a6afa5f4a01c 100644
> --- a/arch/x86/kvm/vmx/vmx.c
> +++ b/arch/x86/kvm/vmx/vmx.c
> @@ -4694,7 +4694,7 @@ static int handle_exception_nmi(struct kvm_vcpu *vcpu)
> return 0;
> }
>
> -static int handle_external_interrupt(struct kvm_vcpu *vcpu)
> +static __always_inline int handle_external_interrupt(struct kvm_vcpu *vcpu)
> {
> ++vcpu->stat.irq_exits;
> return 1;
> @@ -4965,21 +4965,6 @@ void kvm_x86_set_dr7(struct kvm_vcpu *vcpu, unsigned long val)
> vmcs_writel(GUEST_DR7, val);
> }
>
> -static int handle_cpuid(struct kvm_vcpu *vcpu)
> -{
> - return kvm_emulate_cpuid(vcpu);
> -}
> -
> -static int handle_rdmsr(struct kvm_vcpu *vcpu)
> -{
> - return kvm_emulate_rdmsr(vcpu);
> -}
> -
> -static int handle_wrmsr(struct kvm_vcpu *vcpu)
> -{
> - return kvm_emulate_wrmsr(vcpu);
> -}
> -
> static int handle_tpr_below_threshold(struct kvm_vcpu *vcpu)
> {
> kvm_apic_update_ppr(vcpu);
> @@ -4996,11 +4981,6 @@ static int handle_interrupt_window(struct kvm_vcpu *vcpu)
> return 1;
> }
>
> -static int handle_halt(struct kvm_vcpu *vcpu)
> -{
> - return kvm_emulate_halt(vcpu);
> -}
> -
> static int handle_vmcall(struct kvm_vcpu *vcpu)
> {
> return kvm_emulate_hypercall(vcpu);
> @@ -5548,11 +5528,11 @@ static int (*kvm_vmx_exit_handlers[])(struct kvm_vcpu *vcpu) = {
> [EXIT_REASON_IO_INSTRUCTION] = handle_io,
> [EXIT_REASON_CR_ACCESS] = handle_cr,
> [EXIT_REASON_DR_ACCESS] = handle_dr,
> - [EXIT_REASON_CPUID] = handle_cpuid,
> - [EXIT_REASON_MSR_READ] = handle_rdmsr,
> - [EXIT_REASON_MSR_WRITE] = handle_wrmsr,
> + [EXIT_REASON_CPUID] = kvm_emulate_cpuid,
> + [EXIT_REASON_MSR_READ] = kvm_emulate_rdmsr,
> + [EXIT_REASON_MSR_WRITE] = kvm_emulate_wrmsr,
> [EXIT_REASON_PENDING_INTERRUPT] = handle_interrupt_window,
> - [EXIT_REASON_HLT] = handle_halt,
> + [EXIT_REASON_HLT] = kvm_emulate_halt,
> [EXIT_REASON_INVD] = handle_invd,
> [EXIT_REASON_INVLPG] = handle_invlpg,
> [EXIT_REASON_RDPMC] = handle_rdpmc,
>

Queued, thanks.

Paolo