On Fri, Nov 15, 2024 at 09:50:47AM -0800, Pawan Gupta wrote:
> This LGTM.
>
> I think SPECTRE_V2_EIBRS_RETPOLINE is placed in the wrong leg, it
> doesn't need RSB filling on context switch, and only needs VMEXIT_LITE.
> Does below change on top of your patch look okay?
Yeah, I was wondering about that too. Since it changes existing
VMEXIT_LITE behavior I'll make it a separate patch. And I'll probably
do the comment changes in a separate patch as well.
> ---
> diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c
> index 7b9c0a21e478..d3b9a0d7a2b5 100644
> --- a/arch/x86/kernel/cpu/bugs.c
> +++ b/arch/x86/kernel/cpu/bugs.c
> @@ -1622,6 +1622,7 @@ static void __init spectre_v2_mitigate_rsb(enum spectre_v2_mitigation mode)
> case SPECTRE_V2_NONE:
> return;
>
> + case SPECTRE_V2_EIBRS_RETPOLINE:
> case SPECTRE_V2_EIBRS_LFENCE:
> case SPECTRE_V2_EIBRS:
> if (boot_cpu_has_bug(X86_BUG_EIBRS_PBRSB)) {
> @@ -1630,7 +1631,6 @@ static void __init spectre_v2_mitigate_rsb(enum spectre_v2_mitigation mode)
> }
> return;
>
> - case SPECTRE_V2_EIBRS_RETPOLINE:
> case SPECTRE_V2_RETPOLINE:
> case SPECTRE_V2_LFENCE:
> case SPECTRE_V2_IBRS:
--
Josh
