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SubjectRe: [PATCH v9 2/8] KVM: arm/arm64: Re-factor setting the Stage 2 entry to exec on fault
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On 10/31/2018 11:27 PM, Punit Agrawal wrote:
> 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 59595207c5e1..6912529946fb 100644
> --- a/virt/kvm/arm/mmu.c
> +++ b/virt/kvm/arm/mmu.c
> @@ -1475,7 +1475,8 @@ 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, force_pte = false;
> + bool write_fault, writable, force_pte = false;
> + bool exec_fault, needs_exec;

New line not required, still within 80 characters.

> unsigned long mmu_seq;
> gfn_t gfn = fault_ipa >> PAGE_SHIFT;
> struct kvm *kvm = vcpu->kvm;
> @@ -1598,19 +1599,25 @@ 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

Coherent or invalidated with invalidate_icache_guest_page ?

> + * mapping be executable.
> + *
> + * Write faults (!exec_fault && FSC_PERM) are orthogonal to
> + * execute permissions, and we preserve whatever we have.
> + */

Otherwise looks good.

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