From a15f693935a9f1fec8241cafaca27be4483d4464 Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Mon, 23 Oct 2017 17:11:15 +0100 Subject: [PATCH] KVM: arm/arm64: Split dcache/icache flushing As we're about to introduce opportunistic invalidation of the icache, let's split dcache and icache flushing. Acked-by: Christoffer Dall Signed-off-by: Marc Zyngier Signed-off-by: Christoffer Dall --- arch/arm/include/asm/kvm_mmu.h | 60 ++++++++++++++++++++++---------- arch/arm64/include/asm/kvm_mmu.h | 13 +++++-- virt/kvm/arm/mmu.c | 20 ++++++++--- 3 files changed, 67 insertions(+), 26 deletions(-) diff --git a/arch/arm/include/asm/kvm_mmu.h b/arch/arm/include/asm/kvm_mmu.h index fa6f2174276b..9fa4b2520974 100644 --- a/arch/arm/include/asm/kvm_mmu.h +++ b/arch/arm/include/asm/kvm_mmu.h @@ -126,21 +126,12 @@ static inline bool vcpu_has_cache_enabled(struct kvm_vcpu *vcpu) return (vcpu_cp15(vcpu, c1_SCTLR) & 0b101) == 0b101; } -static inline void __coherent_cache_guest_page(struct kvm_vcpu *vcpu, - kvm_pfn_t pfn, - unsigned long size) +static inline void __clean_dcache_guest_page(struct kvm_vcpu *vcpu, + kvm_pfn_t pfn, + unsigned long 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 - * (or another VM) may have used the same page as this guest, and we - * read incorrect data from the icache. If we're using a PIPT cache, - * we can invalidate just that page, but if we are using a VIPT cache - * we need to invalidate the entire icache - damn shame - as written - * in the ARM ARM (DDI 0406C.b - Page B3-1393). - * - * VIVT caches are tagged using both the ASID and the VMID and doesn't - * need any kind of flushing (DDI 0406C.b - Page B3-1392). + * Clean the dcache to the Point of Coherency. * * We need to do this through a kernel mapping (using the * user-space mapping has proved to be the wrong @@ -155,19 +146,52 @@ static inline void __coherent_cache_guest_page(struct kvm_vcpu *vcpu, kvm_flush_dcache_to_poc(va, PAGE_SIZE); - if (icache_is_pipt()) - __cpuc_coherent_user_range((unsigned long)va, - (unsigned long)va + PAGE_SIZE); - size -= PAGE_SIZE; pfn++; kunmap_atomic(va); } +} - if (!icache_is_pipt() && !icache_is_vivt_asid_tagged()) { +static inline void __invalidate_icache_guest_page(struct kvm_vcpu *vcpu, + kvm_pfn_t pfn, + unsigned long 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 + * (or another VM) may have used the same page as this guest, and we + * read incorrect data from the icache. If we're using a PIPT cache, + * we can invalidate just that page, but if we are using a VIPT cache + * we need to invalidate the entire icache - damn shame - as written + * in the ARM ARM (DDI 0406C.b - Page B3-1393). + * + * VIVT caches are tagged using both the ASID and the VMID and doesn't + * need any kind of flushing (DDI 0406C.b - Page B3-1392). + */ + + VM_BUG_ON(size & ~PAGE_MASK); + + if (icache_is_vivt_asid_tagged()) + return; + + if (!icache_is_pipt()) { /* any kind of VIPT cache */ __flush_icache_all(); + return; + } + + /* PIPT cache. As for the d-side, use a temporary kernel mapping. */ + while (size) { + void *va = kmap_atomic_pfn(pfn); + + __cpuc_coherent_user_range((unsigned long)va, + (unsigned long)va + PAGE_SIZE); + + size -= PAGE_SIZE; + pfn++; + + kunmap_atomic(va); } } diff --git a/arch/arm64/include/asm/kvm_mmu.h b/arch/arm64/include/asm/kvm_mmu.h index 672c8684d5c2..8034b96fb3a4 100644 --- a/arch/arm64/include/asm/kvm_mmu.h +++ b/arch/arm64/include/asm/kvm_mmu.h @@ -230,19 +230,26 @@ static inline bool vcpu_has_cache_enabled(struct kvm_vcpu *vcpu) return (vcpu_sys_reg(vcpu, SCTLR_EL1) & 0b101) == 0b101; } -static inline void __coherent_cache_guest_page(struct kvm_vcpu *vcpu, - kvm_pfn_t pfn, - unsigned long size) +static inline void __clean_dcache_guest_page(struct kvm_vcpu *vcpu, + kvm_pfn_t pfn, + unsigned long size) { void *va = page_address(pfn_to_page(pfn)); kvm_flush_dcache_to_poc(va, size); +} +static inline void __invalidate_icache_guest_page(struct kvm_vcpu *vcpu, + kvm_pfn_t pfn, + unsigned long size) +{ if (icache_is_aliasing()) { /* any kind of VIPT cache */ __flush_icache_all(); } else if (is_kernel_in_hyp_mode() || !icache_is_vpipt()) { /* PIPT or VPIPT at EL2 (see comment in __kvm_tlb_flush_vmid_ipa) */ + void *va = page_address(pfn_to_page(pfn)); + flush_icache_range((unsigned long)va, (unsigned long)va + size); } diff --git a/virt/kvm/arm/mmu.c b/virt/kvm/arm/mmu.c index b36945d49986..2174244f6317 100644 --- a/virt/kvm/arm/mmu.c +++ b/virt/kvm/arm/mmu.c @@ -1257,10 +1257,16 @@ void kvm_arch_mmu_enable_log_dirty_pt_masked(struct kvm *kvm, kvm_mmu_write_protect_pt_masked(kvm, slot, gfn_offset, mask); } -static void coherent_cache_guest_page(struct kvm_vcpu *vcpu, kvm_pfn_t pfn, - unsigned long size) +static void clean_dcache_guest_page(struct kvm_vcpu *vcpu, kvm_pfn_t pfn, + unsigned long size) { - __coherent_cache_guest_page(vcpu, pfn, size); + __clean_dcache_guest_page(vcpu, pfn, size); +} + +static void invalidate_icache_guest_page(struct kvm_vcpu *vcpu, kvm_pfn_t pfn, + unsigned long size) +{ + __invalidate_icache_guest_page(vcpu, pfn, size); } static void kvm_send_hwpoison_signal(unsigned long address, @@ -1391,7 +1397,9 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, new_pmd = kvm_s2pmd_mkwrite(new_pmd); kvm_set_pfn_dirty(pfn); } - coherent_cache_guest_page(vcpu, pfn, PMD_SIZE); + clean_dcache_guest_page(vcpu, pfn, PMD_SIZE); + invalidate_icache_guest_page(vcpu, pfn, PMD_SIZE); + ret = stage2_set_pmd_huge(kvm, memcache, fault_ipa, &new_pmd); } else { pte_t new_pte = pfn_pte(pfn, mem_type); @@ -1401,7 +1409,9 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, kvm_set_pfn_dirty(pfn); mark_page_dirty(kvm, gfn); } - coherent_cache_guest_page(vcpu, pfn, PAGE_SIZE); + clean_dcache_guest_page(vcpu, pfn, PAGE_SIZE); + invalidate_icache_guest_page(vcpu, pfn, PAGE_SIZE); + ret = stage2_set_pte(kvm, memcache, fault_ipa, &new_pte, flags); } -- 2.45.2