KVM: x86/pmu: Add support for KVM_X86_PMU_OP_OPTIONAL_RET0

Add definitions for KVM_X86_PMU_OP_OPTIONAL_RET0() to resolve to
__static_call_return0, similar to KVM_X86_OP_OPTIONAL_RET0(). Move the
definition of kvm_pmu_call() to pmu.h, and add declarations for the
static PMU calls in the header to allow making callbacks from the header
in following changes.

Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Yosry Ahmed <yosry@kernel.org>
Link: https://patch.msgid.link/20260527234711.4175166-10-yosry@kernel.org
Signed-off-by: Sean Christopherson <seanjc@google.com>

diff --git a/arch/x86/include/asm/kvm-x86-pmu-ops.h b/arch/x86/include/asm/kvm-x86-pmu-ops.h
index d5452b3433b7d45f477ec14b222ffc87fc0a5601..0616243c84cf9ff98815f3d213383a3c8a0370f0 100644 (file)
--- a/arch/x86/include/asm/kvm-x86-pmu-ops.h
+++ b/arch/x86/include/asm/kvm-x86-pmu-ops.h
@@ -1,6 +1,7 @@
 /* SPDX-License-Identifier: GPL-2.0 */
 #if !defined(KVM_X86_PMU_OP) || \
-    !defined(KVM_X86_PMU_OP_OPTIONAL)
+    !defined(KVM_X86_PMU_OP_OPTIONAL) || \
+    !defined(KVM_X86_PMU_OP_OPTIONAL_RET0)
 #error Missing one or more KVM_X86_PMU_OP #defines
 #else
 
@@ -31,3 +32,4 @@ KVM_X86_PMU_OP(mediated_put)
 
 #undef KVM_X86_PMU_OP
 #undef KVM_X86_PMU_OP_OPTIONAL
+#undef KVM_X86_PMU_OP_OPTIONAL_RET0

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index ef353daeacc958fdc529be965c1c796f0ac917c0..dd761073d618d14ff3e49e1987a91951e6415d9d 100644 (file)
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -2065,7 +2065,6 @@ extern bool __read_mostly enable_device_posted_irqs;
 extern struct kvm_x86_ops kvm_x86_ops;
 
 #define kvm_x86_call(func) static_call(kvm_x86_##func)
-#define kvm_pmu_call(func) static_call(kvm_x86_pmu_##func)
 
 #define KVM_X86_OP(func) \
        DECLARE_STATIC_CALL(kvm_x86_##func, *(((struct kvm_x86_ops *)0)->func));

diff --git a/arch/x86/kvm/pmu.c b/arch/x86/kvm/pmu.c
index 67dbbd4c730367cac5c449a268d79724b9653404..9b7e39610be22d2f151a6cc7e5fd27573f21e455 100644 (file)
--- a/arch/x86/kvm/pmu.c
+++ b/arch/x86/kvm/pmu.c
@@ -98,6 +98,7 @@ static struct kvm_pmu_ops kvm_pmu_ops __read_mostly;
        DEFINE_STATIC_CALL_NULL(kvm_x86_pmu_##func,                          \
                                *(((struct kvm_pmu_ops *)0)->func));
 #define KVM_X86_PMU_OP_OPTIONAL KVM_X86_PMU_OP
+#define KVM_X86_PMU_OP_OPTIONAL_RET0 KVM_X86_PMU_OP
 #include <asm/kvm-x86-pmu-ops.h>
 
 void kvm_pmu_ops_update(const struct kvm_pmu_ops *pmu_ops)
@@ -109,6 +110,9 @@ void kvm_pmu_ops_update(const struct kvm_pmu_ops *pmu_ops)
 #define KVM_X86_PMU_OP(func) \
        WARN_ON(!kvm_pmu_ops.func); __KVM_X86_PMU_OP(func)
 #define KVM_X86_PMU_OP_OPTIONAL __KVM_X86_PMU_OP
+#define KVM_X86_PMU_OP_OPTIONAL_RET0(func) \
+       static_call_update(kvm_x86_pmu_##func, (void *)kvm_pmu_ops.func ? : \
+                                              (void *)__static_call_return0);
 #include <asm/kvm-x86-pmu-ops.h>
 #undef __KVM_X86_PMU_OP
 }

diff --git a/arch/x86/kvm/pmu.h b/arch/x86/kvm/pmu.h
index 0e99022168a85c264bd81aae91ced90a9ce336bf..a062f0bc3dbb1d188cb8dcf992eb6014c4186910 100644 (file)
--- a/arch/x86/kvm/pmu.h
+++ b/arch/x86/kvm/pmu.h
@@ -53,6 +53,14 @@ struct kvm_pmu_ops {
        const u32 MSR_STRIDE;
 };
 
+#define kvm_pmu_call(func) static_call(kvm_x86_pmu_##func)
+
+#define KVM_X86_PMU_OP(func) \
+       DECLARE_STATIC_CALL(kvm_x86_pmu_##func, *(((struct kvm_pmu_ops *)0)->func));
+#define KVM_X86_PMU_OP_OPTIONAL KVM_X86_PMU_OP
+#define KVM_X86_PMU_OP_OPTIONAL_RET0 KVM_X86_PMU_OP
+#include <asm/kvm-x86-pmu-ops.h>
+
 extern bool enable_pmu;
 extern bool enable_mediated_pmu;