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Wed, 25 Feb 2026 10:50:51 +0000 Date: Wed, 25 Feb 2026 10:50:50 +0000 Message-ID: <86a4wx9jw5.wl-maz@kernel.org> From: Marc Zyngier To: Anshuman Khandual Cc: linux-arm-kernel@lists.infradead.org, Catalin Marinas , Will Deacon , Ryan Roberts , Mark Rutland , Oliver Upton , linux-kernel@vger.kernel.org, kvmarm@lists.linux.dev Subject: Re: [PATCH 1/2] arm64/mm: Directly use TTBRx_EL1_ASID_MASK In-Reply-To: <86bjhd9nxq.wl-maz@kernel.org> References: <20260225035157.1159962-1-anshuman.khandual@arm.com> <20260225035157.1159962-2-anshuman.khandual@arm.com> <86bjhd9nxq.wl-maz@kernel.org> User-Agent: Wanderlust/2.15.9 (Almost Unreal) SEMI-EPG/1.14.7 (Harue) FLIM-LB/1.14.9 (=?UTF-8?B?R29qxY0=?=) APEL-LB/10.8 EasyPG/1.0.0 Emacs/30.1 (aarch64-unknown-linux-gnu) MULE/6.0 (HANACHIRUSATO) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 (generated by SEMI-EPG 1.14.7 - "Harue") Content-Type: text/plain; charset=US-ASCII X-SA-Exim-Connect-IP: 185.219.108.64 X-SA-Exim-Rcpt-To: anshuman.khandual@arm.com, linux-arm-kernel@lists.infradead.org, catalin.marinas@arm.com, will@kernel.org, ryan.roberts@arm.com, mark.rutland@arm.com, oupton@kernel.org, linux-kernel@vger.kernel.org, kvmarm@lists.linux.dev X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false On Wed, 25 Feb 2026 09:23:29 +0000, Marc Zyngier wrote: > > On Wed, 25 Feb 2026 03:51:56 +0000, > Anshuman Khandual wrote: > > > > diff --git a/arch/arm64/kvm/at.c b/arch/arm64/kvm/at.c > > index 885bd5bb2f41..d5c342ccf0f9 100644 > > --- a/arch/arm64/kvm/at.c > > +++ b/arch/arm64/kvm/at.c > > @@ -560,7 +560,7 @@ static int walk_s1(struct kvm_vcpu *vcpu, struct s1_walk_info *wi, > > BUG(); > > } > > > > - wr->asid = FIELD_GET(TTBR_ASID_MASK, asid_ttbr); > > + wr->asid = FIELD_GET(TTBRx_EL1_ASID_MASK, asid_ttbr); > > if (!kvm_has_feat_enum(vcpu->kvm, ID_AA64MMFR0_EL1, ASIDBITS, 16) || > > !(tcr & TCR_ASID16)) > > wr->asid &= GENMASK(7, 0); > > diff --git a/arch/arm64/kvm/nested.c b/arch/arm64/kvm/nested.c > > index 620126d1f0dc..82558fb2685f 100644 > > --- a/arch/arm64/kvm/nested.c > > +++ b/arch/arm64/kvm/nested.c > > @@ -1343,7 +1343,7 @@ static bool kvm_vncr_tlb_lookup(struct kvm_vcpu *vcpu) > > vcpu_read_sys_reg(vcpu, TTBR0_EL2)); > > u16 asid; > > > > - asid = FIELD_GET(TTBR_ASID_MASK, ttbr); > > + asid = FIELD_GET(TTBRx_EL1_ASID_MASK, ttbr); > > if (!kvm_has_feat_enum(vcpu->kvm, ID_AA64MMFR0_EL1, ASIDBITS, 16) || > > !(tcr & TCR_ASID16)) > > asid &= GENMASK(7, 0); > > @@ -1459,7 +1459,7 @@ static void kvm_map_l1_vncr(struct kvm_vcpu *vcpu) > > vcpu_read_sys_reg(vcpu, TTBR0_EL2)); > > u16 asid; > > > > - asid = FIELD_GET(TTBR_ASID_MASK, ttbr); > > + asid = FIELD_GET(TTBRx_EL1_ASID_MASK, ttbr); > > if (!kvm_has_feat_enum(vcpu->kvm, ID_AA64MMFR0_EL1, ASIDBITS, 16) || > > !(tcr & TCR_ASID16)) > > asid &= GENMASK(7, 0); > > Given the 3 hunks above, there is clearly a better approach. https://lore.kernel.org/r/20260225104718.14209-1-maz@kernel.org M. -- Without deviation from the norm, progress is not possible.