From: Punit Agrawal <punit.agrawal@arm.com> To: kvmarm@lists.cs.columbia.edu Cc: Punit Agrawal <punit.agrawal@arm.com>, marc.zyngier@arm.com, will.deacon@arm.com, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Christoffer Dall <christoffer.dall@arm.com> Subject: [PATCH v7 3/9] KVM: arm/arm64: Re-factor setting the Stage 2 entry to exec on fault Date: Mon, 24 Sep 2018 18:45:46 +0100 [thread overview] Message-ID: <20180924174552.8387-4-punit.agrawal@arm.com> (raw) In-Reply-To: <20180924174552.8387-1-punit.agrawal@arm.com> Stage 2 fault handler marks a page as executable if it is handling an execution fault or if it was a permission fault in which case the executable bit needs to be preserved. The logic to decide if the page should be marked executable is duplicated for PMD and PTE entries. To avoid creating another copy when support for PUD hugepages is introduced refactor the code to share the checks needed to mark a page table entry as executable. Signed-off-by: Punit Agrawal <punit.agrawal@arm.com> Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com> Cc: Christoffer Dall <christoffer.dall@arm.com> Cc: Marc Zyngier <marc.zyngier@arm.com> --- virt/kvm/arm/mmu.c | 28 +++++++++++++++------------- 1 file changed, 15 insertions(+), 13 deletions(-) diff --git a/virt/kvm/arm/mmu.c b/virt/kvm/arm/mmu.c index 5b76ee204000..ec64d21c6571 100644 --- a/virt/kvm/arm/mmu.c +++ b/virt/kvm/arm/mmu.c @@ -1481,7 +1481,8 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, unsigned long fault_status) { int ret; - bool write_fault, exec_fault, writable, hugetlb = false, force_pte = false; + bool write_fault, writable, hugetlb = false, force_pte = false; + bool exec_fault, needs_exec; unsigned long mmu_seq; gfn_t gfn = fault_ipa >> PAGE_SHIFT; struct kvm *kvm = vcpu->kvm; @@ -1606,19 +1607,25 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, if (exec_fault) invalidate_icache_guest_page(pfn, vma_pagesize); + /* + * If we took an execution fault we have made the + * icache/dcache coherent above and should now let the s2 + * mapping be executable. + * + * Write faults (!exec_fault && FSC_PERM) are orthogonal to + * execute permissions, and we preserve whatever we have. + */ + needs_exec = exec_fault || + (fault_status == FSC_PERM && stage2_is_exec(kvm, fault_ipa)); + if (hugetlb && vma_pagesize == PMD_SIZE) { pmd_t new_pmd = pfn_pmd(pfn, mem_type); new_pmd = pmd_mkhuge(new_pmd); if (writable) new_pmd = kvm_s2pmd_mkwrite(new_pmd); - if (exec_fault) { + if (needs_exec) new_pmd = kvm_s2pmd_mkexec(new_pmd); - } else if (fault_status == FSC_PERM) { - /* Preserve execute if XN was already cleared */ - if (stage2_is_exec(kvm, fault_ipa)) - new_pmd = kvm_s2pmd_mkexec(new_pmd); - } ret = stage2_set_pmd_huge(kvm, memcache, fault_ipa, &new_pmd); } else { @@ -1629,13 +1636,8 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, mark_page_dirty(kvm, gfn); } - if (exec_fault) { + if (needs_exec) new_pte = kvm_s2pte_mkexec(new_pte); - } else if (fault_status == FSC_PERM) { - /* Preserve execute if XN was already cleared */ - if (stage2_is_exec(kvm, fault_ipa)) - new_pte = kvm_s2pte_mkexec(new_pte); - } ret = stage2_set_pte(kvm, memcache, fault_ipa, &new_pte, flags); } -- 2.18.0
WARNING: multiple messages have this Message-ID (diff)
From: punit.agrawal@arm.com (Punit Agrawal) To: linux-arm-kernel@lists.infradead.org Subject: [PATCH v7 3/9] KVM: arm/arm64: Re-factor setting the Stage 2 entry to exec on fault Date: Mon, 24 Sep 2018 18:45:46 +0100 [thread overview] Message-ID: <20180924174552.8387-4-punit.agrawal@arm.com> (raw) In-Reply-To: <20180924174552.8387-1-punit.agrawal@arm.com> Stage 2 fault handler marks a page as executable if it is handling an execution fault or if it was a permission fault in which case the executable bit needs to be preserved. The logic to decide if the page should be marked executable is duplicated for PMD and PTE entries. To avoid creating another copy when support for PUD hugepages is introduced refactor the code to share the checks needed to mark a page table entry as executable. Signed-off-by: Punit Agrawal <punit.agrawal@arm.com> Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com> Cc: Christoffer Dall <christoffer.dall@arm.com> Cc: Marc Zyngier <marc.zyngier@arm.com> --- virt/kvm/arm/mmu.c | 28 +++++++++++++++------------- 1 file changed, 15 insertions(+), 13 deletions(-) diff --git a/virt/kvm/arm/mmu.c b/virt/kvm/arm/mmu.c index 5b76ee204000..ec64d21c6571 100644 --- a/virt/kvm/arm/mmu.c +++ b/virt/kvm/arm/mmu.c @@ -1481,7 +1481,8 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, unsigned long fault_status) { int ret; - bool write_fault, exec_fault, writable, hugetlb = false, force_pte = false; + bool write_fault, writable, hugetlb = false, force_pte = false; + bool exec_fault, needs_exec; unsigned long mmu_seq; gfn_t gfn = fault_ipa >> PAGE_SHIFT; struct kvm *kvm = vcpu->kvm; @@ -1606,19 +1607,25 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, if (exec_fault) invalidate_icache_guest_page(pfn, vma_pagesize); + /* + * If we took an execution fault we have made the + * icache/dcache coherent above and should now let the s2 + * mapping be executable. + * + * Write faults (!exec_fault && FSC_PERM) are orthogonal to + * execute permissions, and we preserve whatever we have. + */ + needs_exec = exec_fault || + (fault_status == FSC_PERM && stage2_is_exec(kvm, fault_ipa)); + if (hugetlb && vma_pagesize == PMD_SIZE) { pmd_t new_pmd = pfn_pmd(pfn, mem_type); new_pmd = pmd_mkhuge(new_pmd); if (writable) new_pmd = kvm_s2pmd_mkwrite(new_pmd); - if (exec_fault) { + if (needs_exec) new_pmd = kvm_s2pmd_mkexec(new_pmd); - } else if (fault_status == FSC_PERM) { - /* Preserve execute if XN was already cleared */ - if (stage2_is_exec(kvm, fault_ipa)) - new_pmd = kvm_s2pmd_mkexec(new_pmd); - } ret = stage2_set_pmd_huge(kvm, memcache, fault_ipa, &new_pmd); } else { @@ -1629,13 +1636,8 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, mark_page_dirty(kvm, gfn); } - if (exec_fault) { + if (needs_exec) new_pte = kvm_s2pte_mkexec(new_pte); - } else if (fault_status == FSC_PERM) { - /* Preserve execute if XN was already cleared */ - if (stage2_is_exec(kvm, fault_ipa)) - new_pte = kvm_s2pte_mkexec(new_pte); - } ret = stage2_set_pte(kvm, memcache, fault_ipa, &new_pte, flags); } -- 2.18.0
next prev parent reply other threads:[~2018-09-24 17:46 UTC|newest] Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top 2018-09-24 17:45 [PATCH v7 0/9] KVM: Support PUD hugepages at stage 2 Punit Agrawal 2018-09-24 17:45 ` Punit Agrawal 2018-09-24 17:45 ` [PATCH v7 1/9] KVM: arm/arm64: Ensure only THP is candidate for adjustment Punit Agrawal 2018-09-24 17:45 ` Punit Agrawal 2018-09-24 20:54 ` Suzuki K Poulose 2018-09-24 20:54 ` Suzuki K Poulose 2018-09-24 17:45 ` [PATCH v7 2/9] KVM: arm/arm64: Share common code in user_mem_abort() Punit Agrawal 2018-09-24 17:45 ` Punit Agrawal 2018-09-24 17:45 ` Punit Agrawal [this message] 2018-09-24 17:45 ` [PATCH v7 3/9] KVM: arm/arm64: Re-factor setting the Stage 2 entry to exec on fault Punit Agrawal 2018-09-24 17:45 ` [PATCH v7 4/9] KVM: arm/arm64: Introduce helpers to manipulate page table entries Punit Agrawal 2018-09-24 17:45 ` Punit Agrawal 2018-09-24 17:45 ` [PATCH v7 5/9] KVM: arm64: Support dirty page tracking for PUD hugepages Punit Agrawal 2018-09-24 17:45 ` Punit Agrawal 2018-09-24 17:45 ` [PATCH v7 6/9] KVM: arm64: Support PUD hugepage in stage2_is_exec() Punit Agrawal 2018-09-24 17:45 ` Punit Agrawal 2018-09-24 17:45 ` [PATCH v7 7/9] KVM: arm64: Support handling access faults for PUD hugepages Punit Agrawal 2018-09-24 17:45 ` Punit Agrawal 2018-09-24 17:45 ` [PATCH v7 8/9] KVM: arm64: Update age handlers to support " Punit Agrawal 2018-09-24 17:45 ` Punit Agrawal 2018-09-24 17:45 ` [PATCH v7 9/9] KVM: arm64: Add support for creating PUD hugepages at stage 2 Punit Agrawal 2018-09-24 17:45 ` Punit Agrawal 2018-09-24 21:21 ` Suzuki K Poulose 2018-09-24 21:21 ` Suzuki K Poulose 2018-09-25 9:21 ` Punit Agrawal 2018-09-25 9:21 ` Punit Agrawal 2018-09-25 9:21 ` Punit Agrawal 2018-09-25 14:37 ` [PATCH v7.1 " Punit Agrawal 2018-09-25 14:37 ` Punit Agrawal 2018-10-01 14:00 ` Punit Agrawal 2018-10-01 14:00 ` Punit Agrawal
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