On 8/26/2024 10:22 AM, Binbin Wu wrote:
Check whether a KVM hypercall needs to exit to userspace or not based on
hypercall_exit_enabled field of struct kvm_arch.
Userspace can request a hypercall to exit to userspace for handling by
enable KVM_CAP_EXIT_HYPERCALL and the enabled hypercall will be set in
hypercall_exit_enabled. Make the check code generic based on it.
Signed-off-by: Binbin Wu <binbin.wu@xxxxxxxxxxxxxxx>
Reviewed-by: Kai Huang <kai.huang@xxxxxxxxx>
---
arch/x86/kvm/x86.c | 5 +++--
arch/x86/kvm/x86.h | 4 ++++
2 files changed, 7 insertions(+), 2 deletions(-)
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 966fb301d44b..e521f14ad2b2 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -10220,8 +10220,9 @@ int kvm_emulate_hypercall(struct kvm_vcpu *vcpu)
cpl = kvm_x86_call(get_cpl)(vcpu);
ret = __kvm_emulate_hypercall(vcpu, nr, a0, a1, a2, a3, op_64_bit, cpl);
- if (nr == KVM_HC_MAP_GPA_RANGE && !ret)
- /* MAP_GPA tosses the request to the user space. */
+ /* Check !ret first to make sure nr is a valid KVM hypercall. */
+ if (!ret && user_exit_on_hypercall(vcpu->kvm, nr))
+ /* The hypercall is requested to exit to userspace. */
Nit: Above comment is unnecessary since the name of
user_exit_on_hypercall() is self documenting.
Otherwise,
Reviewed-by: Xiaoyao Li <xiaoyao.li@xxxxxxxxx>
return 0;
if (!op_64_bit)
diff --git a/arch/x86/kvm/x86.h b/arch/x86/kvm/x86.h
index 6556a43f1915..bc1a9e080acb 100644
--- a/arch/x86/kvm/x86.h
+++ b/arch/x86/kvm/x86.h
@@ -561,4 +561,8 @@ int kvm_sev_es_string_io(struct kvm_vcpu *vcpu, unsigned int size,
unsigned int port, void *data, unsigned int count,
int in);
+static inline bool user_exit_on_hypercall(struct kvm *kvm, unsigned long hc_nr)
+{
+ return kvm->arch.hypercall_exit_enabled & BIT(hc_nr);
+}
#endif
