On 8/14/2024 7:16 AM, Huang, Kai wrote:
On 13/08/2024 5:12 pm, 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>
One nitpicking below:
---
arch/x86/kvm/x86.c | 4 ++--
arch/x86/kvm/x86.h | 7 +++++++
2 files changed, 9 insertions(+), 2 deletions(-)
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index af6c8cf6a37a..6e16c9751af7 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -10226,8 +10226,8 @@ 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. */
+ if (!ret && is_kvm_hc_exit_enabled(vcpu->kvm, nr))
+ /* The hypercall is requested to exit to userspace. */
return 0;
I believe you put "!ret" check first for a reason? Perhaps you can
add a comment.
Yes, check "!ret" first to make sure the input of
is_kvm_hc_exit_enabled() is a valid KVM_HC_*.
Will add a comment.
Thanks.
