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| author | Paolo Bonzini <pbonzini@redhat.com> | 2020-04-13 10:17:58 +0300 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2020-04-14 11:21:21 +0300 |
| commit | f14eec0a32038f2d6c05b8ea91c7701f65ce7418 (patch) | |
| tree | 6bd3c42848e12a26db69f8c145bcdeb402fad7cb /arch/x86/include/asm/nospec-branch.h | |
| parent | 9ef1530c0c1bb182d7f60165946bd027ff49282e (diff) | |
| download | linux-f14eec0a32038f2d6c05b8ea91c7701f65ce7418.tar.xz | |
KVM: SVM: move more vmentry code to assembly
Manipulate IF around vmload/vmsave to remove the confusing usage of
local_irq_enable where interrupts are actually disabled via GIF.
And stuff the RSB immediately without waiting for a RET to avoid
Spectre-v2 attacks.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86/include/asm/nospec-branch.h')
| -rw-r--r-- | arch/x86/include/asm/nospec-branch.h | 21 |
1 files changed, 0 insertions, 21 deletions
diff --git a/arch/x86/include/asm/nospec-branch.h b/arch/x86/include/asm/nospec-branch.h index 07e95dcb40ad..7e9a281e2660 100644 --- a/arch/x86/include/asm/nospec-branch.h +++ b/arch/x86/include/asm/nospec-branch.h @@ -237,27 +237,6 @@ enum ssb_mitigation { extern char __indirect_thunk_start[]; extern char __indirect_thunk_end[]; -/* - * On VMEXIT we must ensure that no RSB predictions learned in the guest - * can be followed in the host, by overwriting the RSB completely. Both - * retpoline and IBRS mitigations for Spectre v2 need this; only on future - * CPUs with IBRS_ALL *might* it be avoided. - */ -static inline void vmexit_fill_RSB(void) -{ -#ifdef CONFIG_RETPOLINE - unsigned long loops; - - asm volatile (ANNOTATE_NOSPEC_ALTERNATIVE - ALTERNATIVE("jmp 910f", - __stringify(__FILL_RETURN_BUFFER(%0, RSB_CLEAR_LOOPS, %1)), - X86_FEATURE_RETPOLINE) - "910:" - : "=r" (loops), ASM_CALL_CONSTRAINT - : : "memory" ); -#endif -} - static __always_inline void alternative_msr_write(unsigned int msr, u64 val, unsigned int feature) { |