Re: [Xen-devel] [PATCH v1 02/15] arm64: Add config for Cavium Thunder erratum 30115

[Manish Jaggi <mjaggi@xxxxxxxxxxxxxxxxxx>]

On 03/20/2018 01:13 PM, Julien Grall wrote:
> Hi,
>
> On 03/16/2018 11:58 AM, Manish Jaggi wrote:
> > Some Cavium Thunder CPUs suffer a problem where a Xen guest may
> > inadvertently cause the host kernel to quit receiving interrupts.
> > This patch adds CONFIG_CAVIUM_ERRATUM_30115. Subsequent patches will
> > provide workaround.
> >
> > Signed-off-by: Manish Jaggi <manish.jaggi@xxxxxxxxxx>
> >
> > diff --git a/docs/misc/arm/silicon-errata.txt 
> > b/docs/misc/arm/silicon-errata.txt
> > index c9854c39f4..a2546d4bb5 100644
> > --- a/docs/misc/arm/silicon-errata.txt
> > +++ b/docs/misc/arm/silicon-errata.txt
> > @@ -48,3 +48,4 @@ stable hypervisors.
> >   | ARM            | Cortex-A57      | #852523         | 
> > N/A                     |
> >   | ARM            | Cortex-A57      | #832075         | 
> > ARM64_ERRATUM_832075    |
> >   | ARM            | Cortex-A57      | #834220         | 
> > ARM64_ERRATUM_834220    |
> > +| CAVIUM         | ThunderX1       | #30115          | 
> > CAVIUM_ERRATUM_30115    |
> > diff --git a/xen/arch/arm/Kconfig b/xen/arch/arm/Kconfig
> > index f58019d6ed..762b761f7d 100644
> > --- a/xen/arch/arm/Kconfig
> > +++ b/xen/arch/arm/Kconfig
> > @@ -169,6 +169,17 @@ config ARM64_ERRATUM_834220
> >           If unsure, say Y.
> >   +config CAVIUM_ERRATUM_30115
> > +    bool "Cavium Erratum 30115"
> > +    depends on HAS_GICV3
> > +    help
> > +      On ThunderX T88 pass 1.x through 2.2, T81 pass 1.0 through
> > +      1.2, and T83 Pass 1.0, guest execution may disable
> > +      interrupts in host. Trapping both GICv3 group-0 and group-1
> > +      accesses sidesteps the issue.
> > +
> > +      If unsure, say Y.
> > +
> >   endmenu
> >     source "common/Kconfig"
> > diff --git a/xen/arch/arm/cpuerrata.c b/xen/arch/arm/cpuerrata.c
> > index fe9e9facbe..d49698f785 100644
> > --- a/xen/arch/arm/cpuerrata.c
> > +++ b/xen/arch/arm/cpuerrata.c
> > @@ -56,6 +56,27 @@ static const struct arm_cpu_capabilities 
> > arm_errata[] = {
> >           MIDR_RANGE(MIDR_CORTEX_A57, 0x00,
> >                      (1 << MIDR_VARIANT_SHIFT) | 2),
> >       },
> > +#endif
> > +#ifdef CONFIG_CAVIUM_ERRATUM_30115
> > +    {
> > +        /* Cavium ThunderX, T88 pass 1.x - 2.2 */
> This is quite odd. You specify a number in the commit message here, 
> but in the previous one you just say "thunderx1". Can you please try 
> to agree on the name? Like the right naming is MIDR_THUNDERX_88.
ThunderX1 is 88xx. Also this patch is using the same patch from linux.
Please see 
https://lists.cs.columbia.edu/pipermail/kvmarm/2017-June/025815.html
> > +        .desc = "Cavium erratum 30115",
> > +        .capability = ARM64_WORKAROUND_CAVIUM_30115,
> > +        MIDR_RANGE(MIDR_THUNDERX, 0x00,
> > +                   (1 << MIDR_VARIANT_SHIFT) | 2),
> > +    },
> > +    {
> > +        /* Cavium ThunderX, T81 pass 1.0 - 1.2 */
> > +        .desc = "Cavium erratum 30115",
> > +        .capability = ARM64_WORKAROUND_CAVIUM_30115,
> > +        MIDR_RANGE(MIDR_THUNDERX_81XX, 0x00, 0x02),
> > +    },
> > +    {
> > +        /* Cavium ThunderX, T83 pass 1.0 */
> > +        .desc = "Cavium erratum 30115",
> > +        .capability = ARM64_WORKAROUND_CAVIUM_30115,
> > +        MIDR_RANGE(MIDR_THUNDERX_83XX, 0x00, 0x00),
> > +    },
> >   #endif
> >       {},
> >   };
> > diff --git a/xen/include/asm-arm/cpuerrata.h 
> > b/xen/include/asm-arm/cpuerrata.h
> > index 8b158429c7..521f03521b 100644
> > --- a/xen/include/asm-arm/cpuerrata.h
> > +++ b/xen/include/asm-arm/cpuerrata.h
> > @@ -41,6 +41,7 @@ static inline bool 
> > check_workaround_##erratum(void)             \
> >     CHECK_WORKAROUND_HELPER(766422, ARM32_WORKAROUND_766422, 
> > CONFIG_ARM_32)
> >   CHECK_WORKAROUND_HELPER(834220, ARM64_WORKAROUND_834220, 
> > CONFIG_ARM_64)
> > +CHECK_WORKAROUND_HELPER(30115, ARM64_WORKAROUND_CAVIUM_30115, 
> > CONFIG_ARM_64)
> Please add cavium_ in the erratum name. So it is easy to know where 
> the erratum is from.
ok
> >     #undef CHECK_WORKAROUND_HELPER
> >   diff --git a/xen/include/asm-arm/cpufeature.h 
> > b/xen/include/asm-arm/cpufeature.h
> > index f00b6dbd39..d409636bf0 100644
> > --- a/xen/include/asm-arm/cpufeature.h
> > +++ b/xen/include/asm-arm/cpufeature.h
> > @@ -42,8 +42,9 @@
> >   #define LIVEPATCH_FEATURE   4
> >   #define SKIP_SYNCHRONIZE_SERROR_ENTRY_EXIT 5
> >   #define SKIP_CTXT_SWITCH_SERROR_SYNC 6
> > +#define ARM64_WORKAROUND_CAVIUM_30115 7
> >   -#define ARM_NCAPS           7
> > +#define ARM_NCAPS           8
> >     #ifndef __ASSEMBLY__
> Cheers,

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxxx
https://lists.xenproject.org/mailman/listinfo/xen-devel