[RFC PATCH 28/73] KVM: x86/PVM: Handle syscall from user mode

Lai Jiangshan
2024-02-26T14:36:09Z

Similar to the vector event from user mode, the syscall event from user
mode follows the PVM event delivery ABI. Additionally, the 32-bit user
mode can only use "INT 0x80" for syscall.

Signed-off-by: Lai Jiangshan <jiangshan.ljs@antgroup.com>
Signed-off-by: Hou Wenlong <houwenlong.hwl@antgroup.com>
---
arch/x86/kvm/pvm/pvm.c | 15 ++++++++++++++-
1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kvm/pvm/pvm.c b/arch/x86/kvm/pvm/pvm.c
index 57d987903791..92eef226df28 100644
--- a/arch/x86/kvm/pvm/pvm.c
+++ b/arch/x86/kvm/pvm/pvm.c
@@ -915,6 +915,15 @@ static void pvm_setup_mce(struct kvm_vcpu *vcpu)
{
}

+static int handle_exit_syscall(struct kvm_vcpu *vcpu)
+{
+ struct vcpu_pvm *pvm = to_pvm(vcpu);
+
+ if (!is_smod(pvm))
+ return do_pvm_user_event(vcpu, PVM_SYSCALL_VECTOR, false, 0);
+ return 1;
+}
+
static int handle_exit_external_interrupt(struct kvm_vcpu *vcpu)
{
++vcpu->stat.irq_exits;
@@ -939,7 +948,11 @@ static int pvm_handle_exit(struct kvm_vcpu *vcpu, fastpath_t exit_fastpath)
struct vcpu_pvm *pvm = to_pvm(vcpu);
u32 exit_reason = pvm->exit_vector;

- if (exit_reason >= FIRST_EXTERNAL_VECTOR && exit_reason < NR_VECTORS)
+ if (exit_reason == PVM_SYSCALL_VECTOR)
+ return handle_exit_syscall(vcpu);
+ else if (exit_reason == IA32_SYSCALL_VECTOR)
+ return do_pvm_event(vcpu, IA32_SYSCALL_VECTOR, false, 0);
+ else if (exit_reason >= FIRST_EXTERNAL_VECTOR && exit_reason < NR_VECTORS)
return handle_exit_external_interrupt(vcpu);
else if (exit_reason == PVM_FAILED_VMENTRY_VECTOR)
return handle_exit_failed_vmentry(vcpu);
--
2.19.1.6.gb485710b