| Message ID | 1391630151-7875-7-git-send-email-marc.zyngier@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Wed, Feb 05, 2014 at 07:55:46PM +0000, Marc Zyngier wrote: > In order for a guest with caches disabled to observe data written > contained in a given page, we need to make sure that page is > committed to memory, and not just hanging in the cache (as guest > accesses are completely bypassing the cache until it decides to > enable it). > > For this purpose, hook into the coherent_cache_guest_page > function and flush the region if the guest SCTLR > register doesn't show the MMU and caches as being enabled. > > Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> > Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/arch/arm/include/asm/kvm_mmu.h b/arch/arm/include/asm/kvm_mmu.h index 0931cda..b62ca91 100644 --- a/arch/arm/include/asm/kvm_mmu.h +++ b/arch/arm/include/asm/kvm_mmu.h @@ -122,9 +122,19 @@ static inline void kvm_set_s2pmd_writable(pmd_t *pmd) struct kvm; +#define kvm_flush_dcache_to_poc(a,l) __cpuc_flush_dcache_area((a), (l)) + +static inline bool vcpu_has_cache_enabled(struct kvm_vcpu *vcpu) +{ + return (vcpu->arch.cp15[c1_SCTLR] & 0b101) == 0b101; +} + static inline void coherent_cache_guest_page(struct kvm_vcpu *vcpu, hva_t hva, unsigned long size) { + if (!vcpu_has_cache_enabled(vcpu)) + kvm_flush_dcache_to_poc((void *)hva, size); + /* * If we are going to insert an instruction page and the icache is * either VIPT or PIPT, there is a potential problem where the host @@ -145,7 +155,6 @@ static inline void coherent_cache_guest_page(struct kvm_vcpu *vcpu, hva_t hva, } } -#define kvm_flush_dcache_to_poc(a,l) __cpuc_flush_dcache_area((a), (l)) #define kvm_virt_to_phys(x) virt_to_idmap((unsigned long)(x)) void stage2_flush_vm(struct kvm *kvm);