[PATCH v4 55/66] KVM: arm64: Allow populating S2 SW bits
From: Marc Zyngier <maz@kernel.org>
Date: 2021-05-10 17:57:08
Also in:
kvm, kvmarm
Subsystem:
arm64 port (aarch64 architecture), kernel virtual machine for arm64 (kvm/arm64), the rest · Maintainers:
Catalin Marinas, Will Deacon, Marc Zyngier, Oliver Upton, Linus Torvalds
The S2 page table code doesn't use the SW bits yet, but we are about to need them to encode some guest Stage-2 information (its mapping size in the form of the TTL encoding). Propagate the SW bits specified by the caller, and store them into the corresponding entry. Signed-off-by: Marc Zyngier <maz@kernel.org> --- arch/arm64/include/asm/kvm_pgtable.h | 10 ++++++++++ arch/arm64/kvm/hyp/pgtable.c | 6 ++++++ 2 files changed, 16 insertions(+)
diff --git a/arch/arm64/include/asm/kvm_pgtable.h b/arch/arm64/include/asm/kvm_pgtable.h
index c3674c47d48c..4f432ea3094c 100644
--- a/arch/arm64/include/asm/kvm_pgtable.h
+++ b/arch/arm64/include/asm/kvm_pgtable.h@@ -92,6 +92,10 @@ struct kvm_pgtable { * @KVM_PGTABLE_PROT_W: Write permission. * @KVM_PGTABLE_PROT_R: Read permission. * @KVM_PGTABLE_PROT_DEVICE: Device attributes. + * @KVM_PGTABLE_PROT_S2_SW0: SW bit 0. + * @KVM_PGTABLE_PROT_S2_SW1: SW bit 1. + * @KVM_PGTABLE_PROT_S2_SW2: SW bit 2. + * @KVM_PGTABLE_PROT_S2_SW3: SW bit 3. */ enum kvm_pgtable_prot { KVM_PGTABLE_PROT_X = BIT(0),
@@ -99,6 +103,12 @@ enum kvm_pgtable_prot { KVM_PGTABLE_PROT_R = BIT(2), KVM_PGTABLE_PROT_DEVICE = BIT(3), + + /* Cunningly, this matches the PTE bits... */ + KVM_PGTABLE_PROT_S2_SW0 = BIT(55), + KVM_PGTABLE_PROT_S2_SW1 = BIT(56), + KVM_PGTABLE_PROT_S2_SW2 = BIT(57), + KVM_PGTABLE_PROT_S2_SW3 = BIT(58), }; #define PAGE_HYP (KVM_PGTABLE_PROT_R | KVM_PGTABLE_PROT_W)
diff --git a/arch/arm64/kvm/hyp/pgtable.c b/arch/arm64/kvm/hyp/pgtable.c
index c37c1dc4feaf..fa85da30c9b8 100644
--- a/arch/arm64/kvm/hyp/pgtable.c
+++ b/arch/arm64/kvm/hyp/pgtable.c@@ -43,6 +43,7 @@ #define KVM_PTE_LEAF_ATTR_HI_S1_XN BIT(54) #define KVM_PTE_LEAF_ATTR_HI_S2_XN BIT(54) +#define KVM_PTE_LEAF_ATTR_HI_S2_SW GENMASK(58, 55) #define KVM_PTE_LEAF_ATTR_S2_PERMS (KVM_PTE_LEAF_ATTR_LO_S2_S2AP_R | \ KVM_PTE_LEAF_ATTR_LO_S2_S2AP_W | \
@@ -539,6 +540,7 @@ static int stage2_set_prot_attr(struct kvm_pgtable *pgt, enum kvm_pgtable_prot p attr |= FIELD_PREP(KVM_PTE_LEAF_ATTR_LO_S2_SH, sh); attr |= KVM_PTE_LEAF_ATTR_LO_S2_AF; + attr |= prot & KVM_PTE_LEAF_ATTR_HI_S2_SW; *ptep = attr; return 0;
@@ -975,6 +977,10 @@ int kvm_pgtable_stage2_relax_perms(struct kvm_pgtable *pgt, u64 addr, if (prot & KVM_PGTABLE_PROT_X) clr |= KVM_PTE_LEAF_ATTR_HI_S2_XN; + /* Always propagate the SW bits */ + clr |= FIELD_PREP(KVM_PTE_LEAF_ATTR_HI_S2_SW, 0xf); + set |= prot & KVM_PTE_LEAF_ATTR_HI_S2_SW; + ret = stage2_update_leaf_attrs(pgt, addr, 1, set, clr, NULL, &level); if (!ret) kvm_call_hyp(__kvm_tlb_flush_vmid_ipa, pgt->mmu, addr, level);
--
2.29.2
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