On 2/18/22 17:29, Sean Christopherson wrote:
On Thu, Feb 17, 2022, Paolo Bonzini wrote:
A few vendor callbacks are only used by VMX, but they return an integer
or bool value. Introduce KVM_X86_OP_OPTIONAL_RET0 for them: if a func is
NULL in struct kvm_x86_ops, it will be changed to __static_call_return0
when updating static calls.
Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
---
arch/x86/include/asm/kvm-x86-ops.h | 15 +++++++++------
arch/x86/include/asm/kvm_host.h | 4 ++++
arch/x86/kvm/svm/avic.c | 5 -----
arch/x86/kvm/svm/svm.c | 20 --------------------
arch/x86/kvm/x86.c | 2 +-
kernel/static_call.c | 1 +
6 files changed, 15 insertions(+), 32 deletions(-)
diff --git a/arch/x86/include/asm/kvm-x86-ops.h b/arch/x86/include/asm/kvm-x86-ops.h
index c0ec066a8599..29affccb353c 100644
--- a/arch/x86/include/asm/kvm-x86-ops.h
+++ b/arch/x86/include/asm/kvm-x86-ops.h
@@ -10,7 +10,9 @@ BUILD_BUG_ON(1)
*
* KVM_X86_OP_OPTIONAL() can be used for those functions that can have
* a NULL definition, for example if "static_call_cond()" will be used
- * at the call sites.
+ * at the call sites. KVM_X86_OP_OPTIONAL_RET0() can be used likewise
+ * to make a definition optional, but in this case the default will
+ * be __static_call_return0.
__static_call_return0()
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index ab1c4778824a..d3da64106685 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -131,6 +131,7 @@ struct kvm_x86_ops kvm_x86_ops __read_mostly;
DEFINE_STATIC_CALL_NULL(kvm_x86_##func, \
*(((struct kvm_x86_ops *)0)->func));
#define KVM_X86_OP_OPTIONAL KVM_X86_OP
+#define KVM_X86_OP_OPTIONAL_RET0 KVM_X86_OP
#include <asm/kvm-x86-ops.h>
EXPORT_STATIC_CALL_GPL(kvm_x86_get_cs_db_l_bits);
EXPORT_STATIC_CALL_GPL(kvm_x86_cache_reg);
@@ -12016,7 +12017,6 @@ void kvm_arch_flush_shadow_memslot(struct kvm *kvm,
static inline bool kvm_guest_apic_has_interrupt(struct kvm_vcpu *vcpu)
{
return (is_guest_mode(vcpu) &&
- kvm_x86_ops.guest_apic_has_interrupt &&
static_call(kvm_x86_guest_apic_has_interrupt)(vcpu));
Can you opportunistically align the indentation and drop the outer parantheses? I.e.
return is_guest_mode(vcpu) &&
static_call(kvm_x86_guest_apic_has_interrupt)(vcpu);
Hmm, I like having the parentheses (despite "return not being a
function") because editors are inconsistent in what indentation to use
after return.
Some use a tab (which does the right thing just by chance with Linux
because "return " is as long as a tab is wide), but vim for example does
the totally awkward
int f()
{
return a &&
b;
}
Of course I can fix the indentation.
Paolo
}
diff --git a/kernel/static_call.c b/kernel/static_call.c
index 43ba0b1e0edb..76abd46fe6ee 100644
--- a/kernel/static_call.c
+++ b/kernel/static_call.c
@@ -503,6 +503,7 @@ long __static_call_return0(void)
{
return 0;
}
+EXPORT_SYMBOL_GPL(__static_call_return0)
This doesn't compile, it needs a semicolon.
