On 2/25/2020 12:17 AM, Sean Christopherson wrote:
On Mon, Feb 24, 2020 at 02:04:46PM +0100, Vitaly Kuznetsov wrote:
Xiaoyao Li <xiaoyao.li@xxxxxxxxx> writes:
On 2/24/2020 6:16 PM, Vitaly Kuznetsov wrote:
Xiaoyao Li <xiaoyao.li@xxxxxxxxx> writes:
...
rip = kvm_rip_read(vcpu);
rip += vmcs_read32(VM_EXIT_INSTRUCTION_LEN);
kvm_rip_write(vcpu, rip);
@@ -5797,6 +5797,7 @@ static int vmx_handle_exit(struct kvm_vcpu *vcpu,
{
struct vcpu_vmx *vmx = to_vmx(vcpu);
u32 exit_reason = vmx->exit_reason;
+ u16 basic_exit_reason = basic(exit_reason);
I don't think renaming local variable is needed, let's just do
'u16 exit_reason = basic_exit_reason(vmx->exit_reason)' and keep the
rest of the code as-is.
No, we can't do this.
It's not just renaming local variable, the full 32-bit exit reason is
used elsewhere in this function that needs the upper 16-bit.
Here variable basic_exit_reason is added for the cases where only basic
exit reason number is needed.
Can we do the other way around, i.e. introduce 'extended_exit_reason'
and use it where all 32 bits are needed? I'm fine with the change, just
trying to minimize the (unneeded) code churn.
100% agree. Even better than adding a second field to vcpu_vmx would be
to make it a union, though we'd probably want to call it something like
full_exit_reason in that case. That should give us compile-time checks on
exit_reason, e.g. if we try to query one of the upper bits using a u16, e.g.
I have thought about union, but it seems
union {
u16 exit_reason;
u32 full_exit_reason;
}
is not a good name. Since there are many codes in vmx.c and nested.c
assume that exit_reason stands for 32-bit EXIT REASON vmcs field as well
as evmcs->vm_exit_reason and vmcs12->vm_exit_reason. Do we really want
to also rename them to full_exit_reason?
Maybe we name it
union {
u16 basic_exit_reason;
u32 exit_reason;
}
as what SDM defines?
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -5818,7 +5818,7 @@ static int vmx_handle_exit(struct kvm_vcpu *vcpu,
if (is_guest_mode(vcpu) && nested_vmx_exit_reflected(vcpu, exit_reason))
return nested_vmx_reflect_vmexit(vcpu, exit_reason);
- if (exit_reason & VMX_EXIT_REASONS_FAILED_VMENTRY) {
+ if (vmx->full_exit_reason & VMX_EXIT_REASONS_FAILED_VMENTRY) {
dump_vmcs();
vcpu->run->exit_reason = KVM_EXIT_FAIL_ENTRY;
vcpu->run->fail_entry.hardware_entry_failure_reason
@@ -6620,11 +6620,12 @@ static void vmx_vcpu_run(struct kvm_vcpu *vcpu)
vmx->nested.nested_run_pending = 0;
vmx->idt_vectoring_info = 0;
- vmx->exit_reason = vmx->fail ? 0xdead : vmcs_read32(VM_EXIT_REASON);
- if ((u16)vmx->exit_reason == EXIT_REASON_MCE_DURING_VMENTRY)
+ vmx->full_exit_reason = vmx->fail ? 0xdead : vmcs_read32(VM_EXIT_REASON);
+ if (vmx->exit_reason == EXIT_REASON_MCE_DURING_VMENTRY)
kvm_machine_check();
- if (vmx->fail || (vmx->exit_reason & VMX_EXIT_REASONS_FAILED_VMENTRY))
+ if (vmx->fail ||
+ (vmx->full_exit_reason & VMX_EXIT_REASONS_FAILED_VMENTRY))
return;
vmx->loaded_vmcs->launched = 1;
diff --git a/arch/x86/kvm/vmx/vmx.h b/arch/x86/kvm/vmx/vmx.h
index 7f42cf3dcd70..60c09640ea59 100644
--- a/arch/x86/kvm/vmx/vmx.h
+++ b/arch/x86/kvm/vmx/vmx.h
@@ -260,7 +260,10 @@ struct vcpu_vmx {
int vpid;
bool emulation_required;
- u32 exit_reason;
+ union {
+ u16 exit_reason;
+ u32 full_exit_reason;
+ }
/* Posted interrupt descriptor */
struct pi_desc pi_desc;
--
Vitaly
