From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sudeep.KarkadaNagesha@arm.com (Sudeep KarkadaNagesha) Date: Wed, 14 Aug 2013 15:23:23 +0100 Subject: [PATCH] ARM64: KVM: Fix coherent_icache_guest_page() for host with external L3-cache. In-Reply-To: <1376480832-18705-1-git-send-email-pranavkumar@linaro.org> References: <1376480832-18705-1-git-send-email-pranavkumar@linaro.org> Message-ID: <520B92DB.5070708@arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 14/08/13 12:47, Pranavkumar Sawargaonkar wrote: > Systems with large external L3-cache (few MBs), might have dirty > content belonging to the guest page in L3-cache. To tackle this, > we need to flush such dirty content from d-cache so that guest > will see correct contents of guest page when guest MMU is disabled. > > The patch fixes coherent_icache_guest_page() for external L3-cache. > I don't understand KVM but the commit message caught my attention. You are referring to clean the external/outer L3 cache but using internal cache maintenance APIs. You should be using outer_cache APIs if you really intend to do outer cache maintenance ? Is the external/outer L3 cache not unified ? Or did you mean to flush d-cache to the point of coherency(external L3 in your case)? If so it's not clear from the commit log. Regards, Sudeep > Signed-off-by: Pranavkumar Sawargaonkar > Signed-off-by: Anup Patel > --- > arch/arm64/include/asm/kvm_mmu.h | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/arch/arm64/include/asm/kvm_mmu.h b/arch/arm64/include/asm/kvm_mmu.h > index efe609c..5129038 100644 > --- a/arch/arm64/include/asm/kvm_mmu.h > +++ b/arch/arm64/include/asm/kvm_mmu.h > @@ -123,6 +123,8 @@ static inline void coherent_icache_guest_page(struct kvm *kvm, gfn_t gfn) > if (!icache_is_aliasing()) { /* PIPT */ > unsigned long hva = gfn_to_hva(kvm, gfn); > flush_icache_range(hva, hva + PAGE_SIZE); > + /* Flush d-cache for systems with external caches. */ > + __flush_dcache_area((void *) hva, PAGE_SIZE); > } else if (!icache_is_aivivt()) { /* non ASID-tagged VIVT */ > /* any kind of VIPT cache */ > __flush_icache_all(); >