From: Marc Zyngier <maz@kernel.org>
To: stable@vger.kernel.org
Cc: Joey Gouly <joey.gouly@arm.com>,
Jonathan Cameron <jonathan.cameron@huawei.com>
Subject: [PATCH 6.18.y 1/5] KVM: arm64: Deduplicate ASID retrieval code
Date: Tue, 21 Jul 2026 10:58:37 +0100 [thread overview]
Message-ID: <20260721095841.2845371-1-maz@kernel.org> (raw)
In-Reply-To: <2026072033-frigidly-corncob-3b28@gregkh>
We currently have three versions of the ASID retrieval code, one
in the S1 walker, and two in the VNCR handling (although the last
two are limited to the EL2&0 translation regime).
Make this code common, and take this opportunity to also simplify
the code a bit while switching over to the TTBRx_EL1_ASID macro.
Reviewed-by: Joey Gouly <joey.gouly@arm.com>
Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
Link: https://patch.msgid.link/20260225104718.14209-1-maz@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
(cherry picked from commit 54e367cb94d6bef941bbc1132d9959dc73bd4b6f)
[maz: cherry-pick as dependency of bb645aa0a4caeaf7f9cd32e9a948594d434c1a8f]
Signed-off-by: Marc Zyngier <maz@kernel.org>
---
arch/arm64/include/asm/kvm_nested.h | 2 +
arch/arm64/kvm/at.c | 27 +------------
arch/arm64/kvm/nested.c | 60 +++++++++++++++--------------
3 files changed, 35 insertions(+), 54 deletions(-)
diff --git a/arch/arm64/include/asm/kvm_nested.h b/arch/arm64/include/asm/kvm_nested.h
index f7c06a840963d..4d7df3aa7dde6 100644
--- a/arch/arm64/include/asm/kvm_nested.h
+++ b/arch/arm64/include/asm/kvm_nested.h
@@ -363,6 +363,8 @@ int kvm_vcpu_allocate_vncr_tlb(struct kvm_vcpu *vcpu);
int kvm_handle_vncr_abort(struct kvm_vcpu *vcpu);
void kvm_handle_s1e2_tlbi(struct kvm_vcpu *vcpu, u32 inst, u64 val);
+u16 get_asid_by_regime(struct kvm_vcpu *vcpu, enum trans_regime regime);
+
#define vncr_fixmap(c) \
({ \
u32 __c = (c); \
diff --git a/arch/arm64/kvm/at.c b/arch/arm64/kvm/at.c
index e6de6aac6ede2..7a3d07ee6a76c 100644
--- a/arch/arm64/kvm/at.c
+++ b/arch/arm64/kvm/at.c
@@ -491,31 +491,8 @@ static int walk_s1(struct kvm_vcpu *vcpu, struct s1_walk_info *wi,
wr->pa |= va & GENMASK_ULL(va_bottom - 1, 0);
wr->nG = (wi->regime != TR_EL2) && (desc & PTE_NG);
- if (wr->nG) {
- u64 asid_ttbr, tcr;
-
- switch (wi->regime) {
- case TR_EL10:
- tcr = vcpu_read_sys_reg(vcpu, TCR_EL1);
- asid_ttbr = ((tcr & TCR_A1) ?
- vcpu_read_sys_reg(vcpu, TTBR1_EL1) :
- vcpu_read_sys_reg(vcpu, TTBR0_EL1));
- break;
- case TR_EL20:
- tcr = vcpu_read_sys_reg(vcpu, TCR_EL2);
- asid_ttbr = ((tcr & TCR_A1) ?
- vcpu_read_sys_reg(vcpu, TTBR1_EL2) :
- vcpu_read_sys_reg(vcpu, TTBR0_EL2));
- break;
- default:
- BUG();
- }
-
- wr->asid = FIELD_GET(TTBR_ASID_MASK, asid_ttbr);
- if (!kvm_has_feat_enum(vcpu->kvm, ID_AA64MMFR0_EL1, ASIDBITS, 16) ||
- !(tcr & TCR_ASID16))
- wr->asid &= GENMASK(7, 0);
- }
+ if (wr->nG)
+ wr->asid = get_asid_by_regime(vcpu, wi->regime);
return 0;
diff --git a/arch/arm64/kvm/nested.c b/arch/arm64/kvm/nested.c
index b1f52f82c9ef6..255a69d03584f 100644
--- a/arch/arm64/kvm/nested.c
+++ b/arch/arm64/kvm/nested.c
@@ -817,6 +817,33 @@ int kvm_inject_s2_fault(struct kvm_vcpu *vcpu, u64 esr_el2)
return kvm_inject_nested_sync(vcpu, esr_el2);
}
+u16 get_asid_by_regime(struct kvm_vcpu *vcpu, enum trans_regime regime)
+{
+ enum vcpu_sysreg ttbr_elx;
+ u64 tcr;
+ u16 asid;
+
+ switch (regime) {
+ case TR_EL10:
+ tcr = vcpu_read_sys_reg(vcpu, TCR_EL1);
+ ttbr_elx = (tcr & TCR_A1) ? TTBR1_EL1 : TTBR0_EL1;
+ break;
+ case TR_EL20:
+ tcr = vcpu_read_sys_reg(vcpu, TCR_EL2);
+ ttbr_elx = (tcr & TCR_A1) ? TTBR1_EL2 : TTBR0_EL2;
+ break;
+ default:
+ BUG();
+ }
+
+ asid = FIELD_GET(TTBRx_EL1_ASID, vcpu_read_sys_reg(vcpu, ttbr_elx));
+ if (!kvm_has_feat_enum(vcpu->kvm, ID_AA64MMFR0_EL1, ASIDBITS, 16) ||
+ !(tcr & TCR_ASID16))
+ asid &= GENMASK(7, 0);
+
+ return asid;
+}
+
static void invalidate_vncr(struct vncr_tlb *vt)
{
vt->valid = false;
@@ -1283,20 +1310,8 @@ static bool kvm_vncr_tlb_lookup(struct kvm_vcpu *vcpu)
if (read_vncr_el2(vcpu) != vt->gva)
return false;
- if (vt->wr.nG) {
- u64 tcr = vcpu_read_sys_reg(vcpu, TCR_EL2);
- u64 ttbr = ((tcr & TCR_A1) ?
- vcpu_read_sys_reg(vcpu, TTBR1_EL2) :
- vcpu_read_sys_reg(vcpu, TTBR0_EL2));
- u16 asid;
-
- asid = FIELD_GET(TTBR_ASID_MASK, ttbr);
- if (!kvm_has_feat_enum(vcpu->kvm, ID_AA64MMFR0_EL1, ASIDBITS, 16) ||
- !(tcr & TCR_ASID16))
- asid &= GENMASK(7, 0);
-
- return asid == vt->wr.asid;
- }
+ if (vt->wr.nG)
+ return get_asid_by_regime(vcpu, TR_EL20) == vt->wr.asid;
return true;
}
@@ -1399,21 +1414,8 @@ static void kvm_map_l1_vncr(struct kvm_vcpu *vcpu)
if (read_vncr_el2(vcpu) != vt->gva)
return;
- if (vt->wr.nG) {
- u64 tcr = vcpu_read_sys_reg(vcpu, TCR_EL2);
- u64 ttbr = ((tcr & TCR_A1) ?
- vcpu_read_sys_reg(vcpu, TTBR1_EL2) :
- vcpu_read_sys_reg(vcpu, TTBR0_EL2));
- u16 asid;
-
- asid = FIELD_GET(TTBR_ASID_MASK, ttbr);
- if (!kvm_has_feat_enum(vcpu->kvm, ID_AA64MMFR0_EL1, ASIDBITS, 16) ||
- !(tcr & TCR_ASID16))
- asid &= GENMASK(7, 0);
-
- if (asid != vt->wr.asid)
- return;
- }
+ if (vt->wr.nG && get_asid_by_regime(vcpu, TR_EL20) != vt->wr.asid)
+ return;
vt->cpu = smp_processor_id();
--
2.47.3
next prev parent reply other threads:[~2026-07-21 9:58 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-07-20 12:22 FAILED: patch "[PATCH] KVM: arm64: nv: Re-translate VNCR before injecting abort" failed to apply to 6.18-stable tree gregkh
2026-07-21 9:58 ` Marc Zyngier [this message]
2026-07-21 9:58 ` [PATCH 6.18.y 2/5] KVM: arm64: nv: Respect read-only PFN when mapping L1 VNCR Marc Zyngier
2026-07-21 9:58 ` [PATCH 6.18.y 3/5] KVM: arm64: nv: Inject SEA if kvm_translate_vncr() can't resolve PFN Marc Zyngier
2026-07-21 9:58 ` [PATCH 6.18.y 4/5] KVM: arm64: nv: Re-translate VNCR before injecting abort Marc Zyngier
2026-07-21 9:58 ` [PATCH 6.18.y 5/5] KVM: arm64: nv: Inject SEA if guest VNCR isn't normal memory Marc Zyngier
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