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KVM: arm64: Decouple output address from the PT descriptor

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Add a helper converting the descriptor into a nicely formed OA,
irrespective of the in-descriptor representation (< 52bit, LPA
or LPA2).

Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: Marc Zyngier <maz@kernel.org>
This commit is contained in:
Marc Zyngier 2025-07-27 18:46:02 +01:00
parent e645226a9c
commit df1d0197a2
1 changed files with 27 additions and 3 deletions
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30
arch/arm64/kvm/at.c
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@ -56,6 +56,29 @@ static bool has_52bit_pa(struct kvm_vcpu *vcpu, struct s1_walk_info *wi, u64 tcr
return (tcr & (wi->regime == TR_EL2 ? TCR_EL2_DS : TCR_DS));
}
static u64 desc_to_oa(struct s1_walk_info *wi, u64 desc)
{
u64 addr;
if (!wi->pa52bit)
return desc & GENMASK_ULL(47, wi->pgshift);
switch (BIT(wi->pgshift)) {
case SZ_4K:
case SZ_16K:
addr = desc & GENMASK_ULL(49, wi->pgshift);
addr |= FIELD_GET(KVM_PTE_ADDR_51_50_LPA2, desc) << 50;
break;
case SZ_64K:
default: /* IMPDEF: treat any other value as 64k */
addr = desc & GENMASK_ULL(47, wi->pgshift);
addr |= FIELD_GET(KVM_PTE_ADDR_51_48, desc) << 48;
break;
}
return addr;
}
/* Return the translation regime that applies to an AT instruction */
static enum trans_regime compute_translation_regime(struct kvm_vcpu *vcpu, u32 op)
{
@ -402,7 +425,7 @@ static int walk_s1(struct kvm_vcpu *vcpu, struct s1_walk_info *wi,
wr->PXNTable |= FIELD_GET(PMD_TABLE_PXN, desc);
}
baddr = desc & GENMASK_ULL(47, wi->pgshift);
baddr = desc_to_oa(wi, desc);
/* Check for out-of-range OA */
if (check_output_size(baddr, wi))
@ -431,7 +454,8 @@ static int walk_s1(struct kvm_vcpu *vcpu, struct s1_walk_info *wi,
goto transfault;
}
if (check_output_size(desc & GENMASK(47, va_bottom), wi))
baddr = desc_to_oa(wi, desc);
if (check_output_size(baddr & GENMASK(52, va_bottom), wi))
goto addrsz;
if (!(desc & PTE_AF)) {
@ -444,7 +468,7 @@ static int walk_s1(struct kvm_vcpu *vcpu, struct s1_walk_info *wi,
wr->failed = false;
wr->level = level;
wr->desc = desc;
wr->pa = desc & GENMASK(47, va_bottom);
wr->pa = baddr & GENMASK(52, va_bottom);
wr->pa |= va & GENMASK_ULL(va_bottom - 1, 0);
wr->nG = (wi->regime != TR_EL2) && (desc & PTE_NG);