From c9afc58cc368623aaa34a62e321eea2a59240f6f Mon Sep 17 00:00:00 2001
From: Sean Christopherson <sean.j.christopherson@intel.com>
Date: Fri, 25 Jan 2019 07:41:05 -0800
Subject: [PATCH] KVM: VMX: Pass "launched" directly to the vCPU-run asm blob
...and remove struct vcpu_vmx's temporary __launched variable.
Eliminating __launched is a bonus, the real motivation is to get to the
point where the only reference to struct vcpu_vmx in the asm code is
to vcpu.arch.regs, which will simplify moving the blob to a proper asm
file. Note that also means this approach is deliberately different than
what is used in nested_vmx_check_vmentry_hw().
Use BL as it is a callee-save register in both 32-bit and 64-bit ABIs,
i.e. it can't be modified by vmx_update_host_rsp(), to avoid having to
temporarily save/restore the launched flag.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Reviewed-by: Jim Mattson <jmattson@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
arch/x86/kvm/vmx/vmx.c | 13 ++++++-------
arch/x86/kvm/vmx/vmx.h | 2 +-
2 files changed, 7 insertions(+), 8 deletions(-)
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 4b8a94fedb769a..996a13ea86cc7c 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -6373,8 +6373,6 @@ void vmx_update_host_rsp(struct vcpu_vmx *vmx, unsigned long host_rsp)
static void __vmx_vcpu_run(struct kvm_vcpu *vcpu, struct vcpu_vmx *vmx)
{
- vmx->__launched = vmx->loaded_vmcs->launched;
-
if (static_branch_unlikely(&vmx_l1d_should_flush))
vmx_l1d_flush(vcpu);
@@ -6395,7 +6393,8 @@ static void __vmx_vcpu_run(struct kvm_vcpu *vcpu, struct vcpu_vmx *vmx)
"mov (%%" _ASM_SP "), %%" _ASM_CX " \n\t"
/* Check if vmlaunch or vmresume is needed */
- "cmpb $0, %c[launched](%%" _ASM_CX ") \n\t"
+ "cmpb $0, %%bl \n\t"
+
/* Load guest registers. Don't clobber flags. */
"mov %c[rax](%%" _ASM_CX "), %%" _ASM_AX " \n\t"
"mov %c[rbx](%%" _ASM_CX "), %%" _ASM_BX " \n\t"
@@ -6471,7 +6470,7 @@ static void __vmx_vcpu_run(struct kvm_vcpu *vcpu, struct vcpu_vmx *vmx)
"xor %%edi, %%edi \n\t"
"xor %%ebp, %%ebp \n\t"
"pop %%" _ASM_BP " \n\t"
- : ASM_CALL_CONSTRAINT,
+ : ASM_CALL_CONSTRAINT, "=b"((int){0}),
#ifdef CONFIG_X86_64
"=D"((int){0})
: "D"(vmx),
@@ -6479,7 +6478,7 @@ static void __vmx_vcpu_run(struct kvm_vcpu *vcpu, struct vcpu_vmx *vmx)
"=a"((int){0})
: "a"(vmx),
#endif
- [launched]"i"(offsetof(struct vcpu_vmx, __launched)),
+ "b"(vmx->loaded_vmcs->launched),
[fail]"i"(offsetof(struct vcpu_vmx, fail)),
[rax]"i"(offsetof(struct vcpu_vmx, vcpu.arch.regs[VCPU_REGS_RAX])),
[rbx]"i"(offsetof(struct vcpu_vmx, vcpu.arch.regs[VCPU_REGS_RBX])),
@@ -6501,10 +6500,10 @@ static void __vmx_vcpu_run(struct kvm_vcpu *vcpu, struct vcpu_vmx *vmx)
[wordsize]"i"(sizeof(ulong))
: "cc", "memory"
#ifdef CONFIG_X86_64
- , "rax", "rbx", "rcx", "rdx", "rsi"
+ , "rax", "rcx", "rdx", "rsi"
, "r8", "r9", "r10", "r11", "r12", "r13", "r14", "r15"
#else
- , "ebx", "ecx", "edx", "edi", "esi"
+ , "ecx", "edx", "edi", "esi"
#endif
);
diff --git a/arch/x86/kvm/vmx/vmx.h b/arch/x86/kvm/vmx/vmx.h
index 8e203b725928a2..6ee6a492efaf6b 100644
--- a/arch/x86/kvm/vmx/vmx.h
+++ b/arch/x86/kvm/vmx/vmx.h
@@ -208,7 +208,7 @@ struct vcpu_vmx {
struct loaded_vmcs vmcs01;
struct loaded_vmcs *loaded_vmcs;
struct loaded_vmcs *loaded_cpu_state;
- bool __launched; /* temporary, used in vmx_vcpu_run */
+
struct msr_autoload {
struct vmx_msrs guest;
struct vmx_msrs host;
--
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