Commit 35a78319 authored by Sean Christopherson's avatar Sean Christopherson Committed by Paolo Bonzini

KVM: SVM: Use asm goto to handle unexpected #UD on SVM instructions

Add svm_asm*() macros, a la the existing vmx_asm*() macros, to handle
faults on SVM instructions instead of using the generic __ex(), a.k.a.
__kvm_handle_fault_on_reboot().  Using asm goto generates slightly
better code as it eliminates the in-line JMP+CALL sequences that are
needed by __kvm_handle_fault_on_reboot() to avoid triggering BUG()
from fixup (which generates bad stack traces).

Using SVM specific macros also drops the last user of __ex() and the
the last asm linkage to kvm_spurious_fault(), and adds a helper for
VMSAVE, which may gain an addition call site in the future (as part
of optimizing the SVM context switching).
Signed-off-by: default avatarSean Christopherson <seanjc@google.com>
Message-Id: <20201231002702.22237077-8-seanjc@google.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 6a289139
......@@ -22,6 +22,7 @@
#include "x86.h"
#include "svm.h"
#include "svm_ops.h"
#include "cpuid.h"
#include "trace.h"
......@@ -2076,7 +2077,7 @@ void sev_es_vcpu_load(struct vcpu_svm *svm, int cpu)
* of which one step is to perform a VMLOAD. Since hardware does not
* perform a VMSAVE on VMRUN, the host savearea must be updated.
*/
asm volatile(__ex("vmsave %0") : : "a" (__sme_page_pa(sd->save_area)) : "memory");
vmsave(__sme_page_pa(sd->save_area));
/*
* Certain MSRs are restored on VMEXIT, only save ones that aren't
......
......@@ -41,6 +41,7 @@
#include "trace.h"
#include "svm.h"
#include "svm_ops.h"
#define __ex(x) __kvm_handle_fault_on_reboot(x)
......@@ -248,21 +249,6 @@ u32 svm_msrpm_offset(u32 msr)
#define MAX_INST_SIZE 15
static inline void clgi(void)
{
asm volatile (__ex("clgi"));
}
static inline void stgi(void)
{
asm volatile (__ex("stgi"));
}
static inline void invlpga(unsigned long addr, u32 asid)
{
asm volatile (__ex("invlpga %1, %0") : : "c"(asid), "a"(addr));
}
static int get_max_npt_level(void)
{
#ifdef CONFIG_X86_64
......
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __KVM_X86_SVM_OPS_H
#define __KVM_X86_SVM_OPS_H
#include <linux/compiler_types.h>
#include <asm/kvm_host.h>
#define svm_asm(insn, clobber...) \
do { \
asm_volatile_goto("1: " __stringify(insn) "\n\t" \
_ASM_EXTABLE(1b, %l[fault]) \
::: clobber : fault); \
return; \
fault: \
kvm_spurious_fault(); \
} while (0)
#define svm_asm1(insn, op1, clobber...) \
do { \
asm_volatile_goto("1: " __stringify(insn) " %0\n\t" \
_ASM_EXTABLE(1b, %l[fault]) \
:: op1 : clobber : fault); \
return; \
fault: \
kvm_spurious_fault(); \
} while (0)
#define svm_asm2(insn, op1, op2, clobber...) \
do { \
asm_volatile_goto("1: " __stringify(insn) " %1, %0\n\t" \
_ASM_EXTABLE(1b, %l[fault]) \
:: op1, op2 : clobber : fault); \
return; \
fault: \
kvm_spurious_fault(); \
} while (0)
static inline void clgi(void)
{
svm_asm(clgi);
}
static inline void stgi(void)
{
svm_asm(stgi);
}
static inline void invlpga(unsigned long addr, u32 asid)
{
svm_asm2(invlpga, "c"(asid), "a"(addr));
}
/*
* Despite being a physical address, the portion of rAX that is consumed by
* VMSAVE, VMLOAD, etc... is still controlled by the effective address size,
* hence 'unsigned long' instead of 'hpa_t'.
*/
static inline void vmsave(unsigned long pa)
{
svm_asm1(vmsave, "a" (pa), "memory");
}
#endif /* __KVM_X86_SVM_OPS_H */
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