Commit c9afc58c authored by Sean Christopherson's avatar Sean Christopherson Committed by Paolo Bonzini
Browse files

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: default avatarSean Christopherson <sean.j.christopherson@intel.com>
Reviewed-by: default avatarJim Mattson <jmattson@google.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent c09b03eb

arch/x86/kvm/vmx/vmx.c

+6 −7
Original line number Diff line number Diff line
@@ -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

	      );

arch/x86/kvm/vmx/vmx.h

+1 −1
Original line number Diff line number Diff line
@@ -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;