| Message ID | 20220307115920.51099-2-likexu@tencent.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | KVM: x86: Use static calls to reduce kvm_pmu_ops overhead | expand |
On Mon, Mar 07, 2022, Like Xu wrote: > From: Like Xu <likexu@tencent.com> > > The kvm_ops_static_call_update() is defined in kvm_host.h. That's > completely unnecessary, it should have exactly one caller, > kvm_arch_hardware_setup(). As a prep match, move > kvm_ops_static_call_update() to x86.c, then it can reference > the kvm_pmu_ops stuff. > > Suggested-by: Sean Christopherson <seanjc@google.com> > Signed-off-by: Like Xu <likexu@tencent.com> > --- Reviewed-by: Sean Christopherson <seanjc@google.com>
On Tue, Mar 29, 2022, Sean Christopherson wrote: > On Mon, Mar 07, 2022, Like Xu wrote: > > From: Like Xu <likexu@tencent.com> > > > > The kvm_ops_static_call_update() is defined in kvm_host.h. That's > > completely unnecessary, it should have exactly one caller, > > kvm_arch_hardware_setup(). As a prep match, move > > kvm_ops_static_call_update() to x86.c, then it can reference > > the kvm_pmu_ops stuff. > > > > Suggested-by: Sean Christopherson <seanjc@google.com> > > Signed-off-by: Like Xu <likexu@tencent.com> > > --- > > Reviewed-by: Sean Christopherson <seanjc@google.com> Actually, I take that back. If we pass in @ops, and do some other minor tweaks along the way, then we can make kvm_pmu_ops static. I'll post a very compile-tested-only v3.1, trying to generate diffs against your series is going to be painful due to conflicts. The changes aren't big, just annoying. Below is the diff for this patch. Then in patch 2, kvm_ops_update() adds a call to kvm_pmu_ops_update(). Patch 3 just tweaks the call to use ops->pmu_ops instead of ops->runtime_ops->pmu_ops. Patch 4 becomes purely code shuffling (I think). --- arch/x86/kvm/x86.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 9cb8672aab92..99aa2d16845a 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -11595,8 +11595,10 @@ void kvm_arch_hardware_disable(void) drop_user_return_notifiers(); } -static inline void kvm_ops_static_call_update(void) +static inline void kvm_ops_update(struct kvm_x86_init_ops *ops) { + memcpy(&kvm_x86_ops, ops->runtime_ops, sizeof(kvm_x86_ops)); + #define __KVM_X86_OP(func) \ static_call_update(kvm_x86_##func, kvm_x86_ops.func); #define KVM_X86_OP(func) \ @@ -11623,8 +11625,7 @@ int kvm_arch_hardware_setup(void *opaque) if (r != 0) return r; - memcpy(&kvm_x86_ops, ops->runtime_ops, sizeof(kvm_x86_ops)); - kvm_ops_static_call_update(); + kvm_ops_update(ops); kvm_register_perf_callbacks(ops->handle_intel_pt_intr); base-commit: bd6b09f0754bea388a189d544ce11d83206579a2 --
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index da2f3a21e37b..fdb62aba73ef 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -1541,20 +1541,6 @@ extern struct kvm_x86_ops kvm_x86_ops; #define KVM_X86_OP_OPTIONAL_RET0 KVM_X86_OP #include <asm/kvm-x86-ops.h> -static inline void kvm_ops_static_call_update(void) -{ -#define __KVM_X86_OP(func) \ - static_call_update(kvm_x86_##func, kvm_x86_ops.func); -#define KVM_X86_OP(func) \ - WARN_ON(!kvm_x86_ops.func); __KVM_X86_OP(func) -#define KVM_X86_OP_OPTIONAL __KVM_X86_OP -#define KVM_X86_OP_OPTIONAL_RET0(func) \ - static_call_update(kvm_x86_##func, (void *)kvm_x86_ops.func ? : \ - (void *)__static_call_return0); -#include <asm/kvm-x86-ops.h> -#undef __KVM_X86_OP -} - #define __KVM_HAVE_ARCH_VM_ALLOC static inline struct kvm *kvm_arch_alloc_vm(void) { diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index f79bf4552082..7b4e84d80b57 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -11507,6 +11507,20 @@ void kvm_arch_hardware_disable(void) drop_user_return_notifiers(); } +static inline void kvm_ops_static_call_update(void) +{ +#define __KVM_X86_OP(func) \ + static_call_update(kvm_x86_##func, kvm_x86_ops.func); +#define KVM_X86_OP(func) \ + WARN_ON(!kvm_x86_ops.func); __KVM_X86_OP(func) +#define KVM_X86_OP_OPTIONAL __KVM_X86_OP +#define KVM_X86_OP_OPTIONAL_RET0(func) \ + static_call_update(kvm_x86_##func, (void *)kvm_x86_ops.func ? : \ + (void *)__static_call_return0); +#include <asm/kvm-x86-ops.h> +#undef __KVM_X86_OP +} + int kvm_arch_hardware_setup(void *opaque) { struct kvm_x86_init_ops *ops = opaque;