Move the big inline assembly block from nested_vmx_check_vmentry_hw
to vmenter.S assembly file, taking into account all ABI requirements.
The new function is modelled after __vmx_vcpu_run, and also calls
vmx_update_host_rsp instead of open-coding the function in assembly.
Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Cc: Sean Christopherson <sean.j.christopherson@xxxxxxxxx>
Signed-off-by: Uros Bizjak <ubizjak@xxxxxxxxx>
---
arch/x86/kvm/vmx/nested.c | 32 +++-----------------------------
arch/x86/kvm/vmx/vmenter.S | 36 ++++++++++++++++++++++++++++++++++++
2 files changed, 39 insertions(+), 29 deletions(-)
diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
index 1bb6b31eb646..7b26e983e31c 100644
--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -3012,6 +3012,8 @@ static int nested_vmx_check_guest_state(struct kvm_vcpu *vcpu,
return 0;
}
+bool __nested_vmx_check_vmentry_hw(struct vcpu_vmx *vmx, bool launched);
+
static int nested_vmx_check_vmentry_hw(struct kvm_vcpu *vcpu)
{
struct vcpu_vmx *vmx = to_vmx(vcpu);
@@ -3050,35 +3052,7 @@ static int nested_vmx_check_vmentry_hw(struct kvm_vcpu *vcpu)
vmx->loaded_vmcs->host_state.cr4 = cr4;
}
- asm(
- "sub $%c[wordsize], %%" _ASM_SP "\n\t" /* temporarily adjust RSP for CALL */
- "cmp %%" _ASM_SP ", %c[host_state_rsp](%[loaded_vmcs]) \n\t"
- "je 1f \n\t"
- __ex("vmwrite %%" _ASM_SP ", %[HOST_RSP]") "\n\t"
- "mov %%" _ASM_SP ", %c[host_state_rsp](%[loaded_vmcs]) \n\t"
- "1: \n\t"
- "add $%c[wordsize], %%" _ASM_SP "\n\t" /* un-adjust RSP */
-
- /* Check if vmlaunch or vmresume is needed */
- "cmpb $0, %c[launched](%[loaded_vmcs])\n\t"
-
- /*
- * VMLAUNCH and VMRESUME clear RFLAGS.{CF,ZF} on VM-Exit, set
- * RFLAGS.CF on VM-Fail Invalid and set RFLAGS.ZF on VM-Fail
- * Valid. vmx_vmenter() directly "returns" RFLAGS, and so the
- * results of VM-Enter is captured via CC_{SET,OUT} to vm_fail.
- */
- "call vmx_vmenter\n\t"
-
- CC_SET(be)
- : ASM_CALL_CONSTRAINT, CC_OUT(be) (vm_fail)
- : [HOST_RSP]"r"((unsigned long)HOST_RSP),
- [loaded_vmcs]"r"(vmx->loaded_vmcs),
- [launched]"i"(offsetof(struct loaded_vmcs, launched)),
- [host_state_rsp]"i"(offsetof(struct loaded_vmcs, host_state.rsp)),
- [wordsize]"i"(sizeof(ulong))
- : "memory"
- );
+ vm_fail = __nested_vmx_check_vmentry_hw(vmx, vmx->loaded_vmcs->launched);
if (vmx->msr_autoload.host.nr)
vmcs_write32(VM_EXIT_MSR_LOAD_COUNT, vmx->msr_autoload.host.nr);
diff --git a/arch/x86/kvm/vmx/vmenter.S b/arch/x86/kvm/vmx/vmenter.S
index 799db084a336..9fdcbd9320dc 100644
--- a/arch/x86/kvm/vmx/vmenter.S
+++ b/arch/x86/kvm/vmx/vmenter.S
@@ -234,6 +234,42 @@ SYM_FUNC_START(__vmx_vcpu_run)
jmp 1b
SYM_FUNC_END(__vmx_vcpu_run)
+/**
+ * __nested_vmx_check_vmentry_hw - Run a vCPU via a transition to
+ * a nested VMX guest mode
+ * @vmx: struct vcpu_vmx * (forwarded to vmx_update_host_rsp)
+ * @launched: %true if the VMCS has been launched
+ *
+ * Returns:
+ * 0 on VM-Exit, 1 on VM-Fail
+ */
+SYM_FUNC_START(__nested_vmx_check_vmentry_hw)
+ push %_ASM_BP
+ mov %_ASM_SP, %_ASM_BP
+
+ push %_ASM_BX
+
+ /* Copy @launched to BL, _ASM_ARG2 is volatile. */
+ mov %_ASM_ARG2B, %bl
+
+ /* Adjust RSP to account for the CALL to vmx_vmenter(). */
+ lea -WORD_SIZE(%_ASM_SP), %_ASM_ARG2
+ call vmx_update_host_rsp
+
+ /* Check if vmlaunch or vmresume is needed */
+ cmpb $0, %bl
+
+ /* Enter guest mode */
+ call vmx_vmenter
+
+ /* Return 0 on VM-Exit, 1 on VM-Fail */
+ setbe %al
+
+ pop %_ASM_BX
+
+ pop %_ASM_BP
+ ret
+SYM_FUNC_END(__nested_vmx_check_vmentry_hw)
.section .text, "ax"
--
2.26.2
