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Commit 64723cd3 authored by Uros Bizjak's avatar Uros Bizjak Committed by Greg Kroah-Hartman
Browse files

KVM/nVMX: Use __vmx_vcpu_run in nested_vmx_check_vmentry_hw 



commit 150f17bfab37e981ba03b37440638138ff2aa9ec upstream.

Replace inline assembly in nested_vmx_check_vmentry_hw
with a call to __vmx_vcpu_run.  The function is not
performance critical, so (double) GPR save/restore
in __vmx_vcpu_run can be tolerated, as far as performance
effects are concerned.

Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Sean Christopherson <seanjc@google.com>
Reviewed-and-tested-by: default avatarSean Christopherson <seanjc@google.com>
Signed-off-by: default avatarUros Bizjak <ubizjak@gmail.com>
[sean: dropped versioning info from changelog]
Signed-off-by: default avatarSean Christopherson <seanjc@google.com>
Message-Id: <20201231002702.2223707-5-seanjc@google.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
[cascardo: small fixups]
Signed-off-by: default avatarThadeu Lima de Souza Cascardo <cascardo@canonical.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 57ba312f

arch/x86/kvm/vmx/nested.c

+3 −29
Original line number Diff line number Diff line
@@ -11,6 +11,7 @@ 
#include "mmu.h"

#include "nested.h"

#include "trace.h"

#include "vmx.h"

#include "x86.h"



static bool __read_mostly enable_shadow_vmcs = 1;
@@ -2863,35 +2864,8 @@ 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 = __vmx_vcpu_run(vmx, (unsigned long *)&vcpu->arch.regs,

				 vmx->loaded_vmcs->launched);



	if (vmx->msr_autoload.host.nr)

		vmcs_write32(VM_EXIT_MSR_LOAD_COUNT, vmx->msr_autoload.host.nr);

arch/x86/kvm/vmx/vmx.c

+0 −2
Original line number Diff line number Diff line
@@ -6540,8 +6540,6 @@ void vmx_update_host_rsp(struct vcpu_vmx *vmx, unsigned long host_rsp) 
	}

}



bool __vmx_vcpu_run(struct vcpu_vmx *vmx, unsigned long *regs, bool launched);



static void vmx_vcpu_run(struct kvm_vcpu *vcpu)

{

	struct vcpu_vmx *vmx = to_vmx(vcpu);

arch/x86/kvm/vmx/vmx.h

+1 −0
Original line number Diff line number Diff line
@@ -336,6 +336,7 @@ void vmx_set_virtual_apic_mode(struct kvm_vcpu *vcpu); 
struct shared_msr_entry *find_msr_entry(struct vcpu_vmx *vmx, u32 msr);

void pt_update_intercept_for_msr(struct vcpu_vmx *vmx);

void vmx_update_host_rsp(struct vcpu_vmx *vmx, unsigned long host_rsp);

bool __vmx_vcpu_run(struct vcpu_vmx *vmx, unsigned long *regs, bool launched);



#define POSTED_INTR_ON  0

#define POSTED_INTR_SN  1