linux-kernel - [RFC PATCH 08/16] KVM: arm64: Add helper to get permission fault granule from ESR

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20250821210042.3451147-9-seanjc@google.com>
Date: Thu, 21 Aug 2025 14:00:34 -0700
From: Sean Christopherson <seanjc@...gle.com>
To: Marc Zyngier <maz@...nel.org>, Oliver Upton <oliver.upton@...ux.dev>
Cc: linux-arm-kernel@...ts.infradead.org, kvmarm@...ts.linux.dev, 
	linux-kernel@...r.kernel.org, Sean Christopherson <seanjc@...gle.com>, 
	James Houghton <jthoughton@...gle.com>
Subject: [RFC PATCH 08/16] KVM: arm64: Add helper to get permission fault
 granule from ESR

Extract KVM's code for getting the granule for a permission fault into a
standalone API that takes in a raw ESR, so that KVM can get the granule
from a local copy of the ESR instead of re-retrieving the value from the
vCPU.

No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@...gle.com>
---
 arch/arm64/include/asm/esr.h         | 6 ++++++
 arch/arm64/include/asm/kvm_emulate.h | 2 +-
 2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/include/asm/esr.h b/arch/arm64/include/asm/esr.h
index e1deed824464..5bb99cfd184a 100644
--- a/arch/arm64/include/asm/esr.h
+++ b/arch/arm64/include/asm/esr.h
@@ -8,6 +8,7 @@
 #define __ASM_ESR_H
 
 #include <asm/memory.h>
+#include <asm/pgtable-hwdef.h>
 #include <asm/sysreg.h>
 
 #define ESR_ELx_EC_UNKNOWN	UL(0x00)
@@ -478,6 +479,11 @@ static inline bool esr_fsc_is_permission_fault(unsigned long esr)
 	       (esr == ESR_ELx_FSC_PERM_L(0));
 }
 
+static inline u64 esr_fsc_perm_fault_granule(unsigned long esr)
+{
+	return BIT(ARM64_HW_PGTABLE_LEVEL_SHIFT(esr & ESR_ELx_FSC_LEVEL));
+}
+
 static inline bool esr_fsc_is_access_flag_fault(unsigned long esr)
 {
 	esr = esr & ESR_ELx_FSC;
diff --git a/arch/arm64/include/asm/kvm_emulate.h b/arch/arm64/include/asm/kvm_emulate.h
index fa8a08a1ccd5..8065f54927cb 100644
--- a/arch/arm64/include/asm/kvm_emulate.h
+++ b/arch/arm64/include/asm/kvm_emulate.h
@@ -455,7 +455,7 @@ u64 kvm_vcpu_trap_get_perm_fault_granule(const struct kvm_vcpu *vcpu)
 	unsigned long esr = kvm_vcpu_get_esr(vcpu);
 
 	BUG_ON(!esr_fsc_is_permission_fault(esr));
-	return BIT(ARM64_HW_PGTABLE_LEVEL_SHIFT(esr & ESR_ELx_FSC_LEVEL));
+	return esr_fsc_perm_fault_granule(esr);
 }
 
 static __always_inline bool kvm_vcpu_abt_issea(const struct kvm_vcpu *vcpu)
-- 
2.51.0.261.g7ce5a0a67e-goog