Re: [PATCH 1/2] MIPS: KVM: use common EHINV aware UNIQUE_ENTRYHI

[Markos Chandras <Markos.Chandras@imgtec.com>]

On 01/15/2014 10:11 AM, James Hogan wrote:
> When KVM is enabled and TLB invalidation is supported,
> kvm_mips_flush_host_tlb() can cause a machine check exception due to
> multiple matching TLB entries. This can occur on shutdown even when KVM
> hasn't been actively used.
>
> Commit adb78de9eae8 (MIPS: mm: Move UNIQUE_ENTRYHI macro to a header
> file) created a common UNIQUE_ENTRYHI in asm/tlb.h but it didn't update
> the copy of UNIQUE_ENTRYHI in kvm_tlb.c to use it.
>
> Commit 36b175451399 (MIPS: tlb: Set the EHINV bit for TLBINVF cores when
> invalidating the TLB) later added TLB invalidation (EHINV) support to
> the common UNIQUE_ENTRYHI.
>
> Therefore make kvm_tlb.c use the EHINV aware UNIQUE_ENTRYHI
> implementation in asm/tlb.h too.
>
> Signed-off-by: James Hogan <james.hogan@imgtec.com>
> Cc: Ralf Baechle <ralf@linux-mips.org>
> Cc: linux-mips@linux-mips.org
> Cc: Gleb Natapov <gleb@redhat.com>
> Cc: Paolo Bonzini <pbonzini@redhat.com>
> Cc: kvm@vger.kernel.org
> Cc: Markos Chandras <markos.chandras@imgtec.com>
> Cc: Sanjay Lal <sanjayl@kymasys.com>
> ---
> This is based on John Crispin's mips-next-3.14 branch.
>
> I do not object to it being squashed into commit adb78de9eae8 (MIPS: mm:
> Move UNIQUE_ENTRYHI macro to a header file) since that commit hasn't
> reached mainline yet.
> ---
>   arch/mips/kvm/kvm_tlb.c | 4 +---
>   1 file changed, 1 insertion(+), 3 deletions(-)
>
> diff --git a/arch/mips/kvm/kvm_tlb.c b/arch/mips/kvm/kvm_tlb.c
> index c777dd36d4a8..52083ea7fddd 100644
> --- a/arch/mips/kvm/kvm_tlb.c
> +++ b/arch/mips/kvm/kvm_tlb.c
> @@ -25,6 +25,7 @@
>   #include <asm/mmu_context.h>
>   #include <asm/pgtable.h>
>   #include <asm/cacheflush.h>
> +#include <asm/tlb.h>
>
>   #undef CONFIG_MIPS_MT
>   #include <asm/r4kcache.h>
> @@ -35,9 +36,6 @@
>
>   #define PRIx64 "llx"
>
> -/* Use VZ EntryHi.EHINV to invalidate TLB entries */
> -#define UNIQUE_ENTRYHI(idx) (CKSEG0 + ((idx) << (PAGE_SHIFT + 1)))
> -
>   atomic_t kvm_mips_instance;
>   EXPORT_SYMBOL(kvm_mips_instance);
>
>

Thanks. That looks good to me.

Reviewed-by: Markos Chandras <markos.chandras@imgtec.com>

-- 
markos