KVM/nVMX: Use __vmx_vcpu_run in nested_vmx_check_vmentry_hw

commit 8c807924365df2daeb7fe48ac0555f140085fa8f 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>

diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
index 34ee4835b01776344ddffa693dc9778fbc65a621..e1947ef3cd7b5e45dead4e978d6ac9096dbaafe8 100644 (file)
--- 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(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);

diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 0127333609bb37334152d8f925e421e164867344..fd3fb3cf026494bd539e7df7cf4f44a606e49249 100644 (file)
--- 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 *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);

diff --git a/arch/x86/kvm/vmx/vmx.h b/arch/x86/kvm/vmx/vmx.h
index 7a3362ab59867b14713f815cb670a6cd55489921..a6a35dc3743e93abd092c2c168c6fd15cbb46b02 100644 (file)
--- 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 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