linux/arch/x86/kvm/svm/svm_ops.h
Paolo Bonzini e287bd005a KVM: SVM: restore host save area from assembly
Allow access to the percpu area via the GS segment base, which is
needed in order to access the saved host spec_ctrl value.  In linux-next
FILL_RETURN_BUFFER also needs to access percpu data.

For simplicity, the physical address of the save area is added to struct
svm_cpu_data.

Cc: stable@vger.kernel.org
Fixes: a149180fbc ("x86: Add magic AMD return-thunk")
Reported-by: Nathan Chancellor <nathan@kernel.org>
Analyzed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-11-09 12:25:33 -05:00

65 lines
1.4 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __KVM_X86_SVM_OPS_H
#define __KVM_X86_SVM_OPS_H
#include <linux/compiler_types.h>
#include "x86.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 __always_inline void vmsave(unsigned long pa)
{
svm_asm1(vmsave, "a" (pa), "memory");
}
#endif /* __KVM_X86_SVM_OPS_H */