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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>
hifive-unleashed-5.1
Sean Christopherson 2019-01-25 07:41:05 -08:00 committed by Paolo Bonzini
parent c09b03eb7f
commit c9afc58cc3
2 changed files with 7 additions and 8 deletions
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13
arch/x86/kvm/vmx/vmx.c
View File

@ -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
);

2
arch/x86/kvm/vmx/vmx.h
View File

@ -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;