Re: [PATCH 05/14] KVM: arm64: Don't overwrite ignored bits with owner id
From: Marc Zyngier <maz@kernel.org>
Date: 2021-07-19 12:55:51
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On Mon, 19 Jul 2021 11:47:26 +0100, Quentin Perret [off-list ref] wrote:
The nVHE protected mode uses invalid mappings in the host stage-2 page-table to track the owner of each page in the system. In order to allow the usage of ignored bits (a.k.a. software bits) in these mappings, move the owner encoding away from the top bits.
But that's exactly what the current situation is allowing: the use of the SW bits. I am guessing that what you really mean is that you want to *preserve* the SW bits from an existing mapping and use other bits when the mapping is invalid? Thanks, M.
quoted hunk ↗ jump to hunk
Signed-off-by: Quentin Perret <redacted> --- arch/arm64/kvm/hyp/pgtable.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)diff --git a/arch/arm64/kvm/hyp/pgtable.c b/arch/arm64/kvm/hyp/pgtable.c index a60653cbd8e5..a0ac8c2bc174 100644 --- a/arch/arm64/kvm/hyp/pgtable.c +++ b/arch/arm64/kvm/hyp/pgtable.c@@ -50,7 +50,7 @@ KVM_PTE_LEAF_ATTR_LO_S2_S2AP_W | \ KVM_PTE_LEAF_ATTR_HI_S2_XN) -#define KVM_INVALID_PTE_OWNER_MASK GENMASK(63, 56) +#define KVM_INVALID_PTE_OWNER_MASK GENMASK(9, 2) #define KVM_MAX_OWNER_ID 1 struct kvm_pgtable_walk_data {-- 2.32.0.402.g57bb445576-goog
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