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KVM: x86: Kill off __ex() and __kvm_handle_fault_on_reboot()

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Remove the __kvm_handle_fault_on_reboot() and __ex() macros now that all
VMX and SVM instructions use asm goto to handle the fault (or in the
case of VMREAD, completely custom logic).  Drop kvm_spurious_fault()'s
asmlinkage annotation as __kvm_handle_fault_on_reboot() was the only
flow that invoked it from assembly code.

Cc: Uros Bizjak <ubizjak@gmail.com>
Cc: Like Xu <like.xu.linux@gmail.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20210809173955.1710866-2-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Sean Christopherson 2021-08-09 10:39:54 -07:00 committed by Paolo Bonzini
parent 2fba4fc155
commit ad0577c375
5 changed files with 9 additions and 31 deletions
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25
arch/x86/include/asm/kvm_host.h
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@ -1811,30 +1811,7 @@ enum {
#define kvm_arch_vcpu_memslots_id(vcpu) ((vcpu)->arch.hflags & HF_SMM_MASK ? 1 : 0)
#define kvm_memslots_for_spte_role(kvm, role) __kvm_memslots(kvm, (role).smm)
asmlinkage void kvm_spurious_fault(void);
/*
* Hardware virtualization extension instructions may fault if a
* reboot turns off virtualization while processes are running.
* Usually after catching the fault we just panic; during reboot
* instead the instruction is ignored.
*/
#define __kvm_handle_fault_on_reboot(insn) \
"666: \n\t" \
insn "\n\t" \
"jmp 668f \n\t" \
"667: \n\t" \
"1: \n\t" \
".pushsection .discard.instr_begin \n\t" \
".long 1b - . \n\t" \
".popsection \n\t" \
"call kvm_spurious_fault \n\t" \
"1: \n\t" \
".pushsection .discard.instr_end \n\t" \
".long 1b - . \n\t" \
".popsection \n\t" \
"668: \n\t" \
_ASM_EXTABLE(666b, 667b)
void kvm_spurious_fault(void);
#define KVM_ARCH_WANT_MMU_NOTIFIER

2
arch/x86/kvm/svm/sev.c
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@ -28,8 +28,6 @@
#include "cpuid.h"
#include "trace.h"
#define __ex(x) __kvm_handle_fault_on_reboot(x)
#ifndef CONFIG_KVM_AMD_SEV
/*
* When this config is not defined, SEV feature is not supported and APIs in

2
arch/x86/kvm/svm/svm.c
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@ -46,8 +46,6 @@
#include "kvm_onhyperv.h"
#include "svm_onhyperv.h"
#define __ex(x) __kvm_handle_fault_on_reboot(x)
MODULE_AUTHOR("Qumranet");
MODULE_LICENSE("GPL");

2
arch/x86/kvm/vmx/vmx_ops.h
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@ -10,8 +10,6 @@
#include "evmcs.h"
#include "vmcs.h"
#define __ex(x) __kvm_handle_fault_on_reboot(x)
asmlinkage void vmread_error(unsigned long field, bool fault);
__attribute__((regparm(0))) void vmread_error_trampoline(unsigned long field,
bool fault);

9
arch/x86/kvm/x86.c
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@ -486,7 +486,14 @@ int kvm_set_apic_base(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
}
EXPORT_SYMBOL_GPL(kvm_set_apic_base);
asmlinkage __visible noinstr void kvm_spurious_fault(void)
/*
* Handle a fault on a hardware virtualization (VMX or SVM) instruction.
*
* Hardware virtualization extension instructions may fault if a reboot turns
* off virtualization while processes are running. Usually after catching the
* fault we just panic; during reboot instead the instruction is ignored.
*/
noinstr void kvm_spurious_fault(void)
{
/* Fault while not rebooting. We want the trace. */
BUG_ON(!kvm_rebooting);