lkml.org 
[lkml]   [2022]   [Oct]   [5]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 5.4 25/51] KVM/nVMX: Use __vmx_vcpu_run in nested_vmx_check_vmentry_hw
Date
From: Uros Bizjak <ubizjak@gmail.com>

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: Sean Christopherson <seanjc@google.com>
Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
[sean: dropped versioning info from changelog]
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20201231002702.2223707-5-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
[cascardo: small fixups]
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
arch/x86/kvm/vmx/nested.c | 32 +++-----------------------------
arch/x86/kvm/vmx/vmx.c | 2 --
arch/x86/kvm/vmx/vmx.h | 1 +
3 files changed, 4 insertions(+), 31 deletions(-)

--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -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(s
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);
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -6540,8 +6540,6 @@ void vmx_update_host_rsp(struct vcpu_vmx
}
}

-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);
--- a/arch/x86/kvm/vmx/vmx.h
+++ b/arch/x86/kvm/vmx/vmx.h
@@ -336,6 +336,7 @@ void vmx_set_virtual_apic_mode(struct kv
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

\
 
 \ /
  Last update: 2022-10-05 13:36    [W:0.504 / U:1.496 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site