[PATCH 1/3] KVM: arm64: Make ID_PFR1_EL1.GIC writable
From: Marc Zyngier <maz@kernel.org>
Date: 2025-10-13 08:32:18
Also in:
kvm, kvmarm, stable
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
Similarly to ID_AA64PFR0_EL1.GIC, relax ID_PFR1_EL1.GIC to be writable.
Fixes: 5cb57a1aff755 ("KVM: arm64: Zero ID_AA64PFR0_EL1.GIC when no GICv3 is presented to the guest")
Reported-by: Peter Maydell <redacted>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Cc: stable@vger.kernel.org
---
arch/arm64/kvm/sys_regs.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)
diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index b29f72478a50d..73dcefe51a3e7 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c@@ -2528,6 +2528,12 @@ static bool bad_redir_trap(struct kvm_vcpu *vcpu, .val = mask, \ } +#define AA32_ID_WRITABLE(name, mask) { \ + ID_DESC(name), \ + .visibility = aa32_id_visibility, \ + .val = mask, \ +} + /* sys_reg_desc initialiser for cpufeature ID registers that need filtering */ #define ID_FILTERED(sysreg, name, mask) { \ ID_DESC(sysreg), \
@@ -3040,7 +3046,7 @@ static const struct sys_reg_desc sys_reg_descs[] = { /* AArch64 mappings of the AArch32 ID registers */ /* CRm=1 */ AA32_ID_SANITISED(ID_PFR0_EL1), - AA32_ID_SANITISED(ID_PFR1_EL1), + AA32_ID_WRITABLE(ID_PFR1_EL1, ID_PFR1_EL1_GIC), { SYS_DESC(SYS_ID_DFR0_EL1), .access = access_id_reg, .get_user = get_id_reg,
--
2.47.3