[RFC PATCH 14/22] KVM: x86: Introduce kvm_user_return_notifier_register()

Mingwei Zhang
2024-11-21T18:53:43Z

From: Jim Mattson <jmattson@google.com>

Factor out user return notifier registration logic from
kvm_set_user_return_msr() into a separate helper function to prepare
for the registration of KVM's user return notifier from
kvm_load_guest_aperfmperf().

No functional change intended.

Signed-off-by: Jim Mattson <jmattson@google.com>
---
arch/x86/kvm/x86.c | 15 ++++++++++-----
1 file changed, 10 insertions(+), 5 deletions(-)

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index acfa9ecc5bc36..6df8f21b83eb1 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -637,6 +637,15 @@ static void kvm_user_return_msr_cpu_online(void)
}
}

+static void kvm_user_return_notifier_register(struct kvm_user_return_msrs *msrs)
+{
+ if (!msrs->registered) {
+ msrs->urn.on_user_return = kvm_on_user_return;
+ user_return_notifier_register(&msrs->urn);
+ msrs->registered = true;
+ }
+}
+
int kvm_set_user_return_msr(unsigned slot, u64 value, u64 mask)
{
struct kvm_user_return_msrs *msrs = this_cpu_ptr(user_return_msrs);
@@ -650,11 +659,7 @@ int kvm_set_user_return_msr(unsigned slot, u64 value, u64 mask)
return 1;

msrs->values[slot].curr = value;
- if (!msrs->registered) {
- msrs->urn.on_user_return = kvm_on_user_return;
- user_return_notifier_register(&msrs->urn);
- msrs->registered = true;
- }
+ kvm_user_return_notifier_register(msrs);
return 0;
}
EXPORT_SYMBOL_GPL(kvm_set_user_return_msr);
--
2.47.0.371.ga323438b13-goog