Thread (12 messages) read the whole thread 12 messages, 2 authors, 2024-08-02
STALE729d

Revision v2 of 4 in this series.

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[PATCH v2 6/8] KVM: arm64: Expose ID_AA64FPFR0_EL1 as a writable ID reg

From: Marc Zyngier <maz@kernel.org>
Date: 2024-08-01 09:23:11
Also in: kvm, kvmarm
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

ID_AA64FPFR0_EL1 contains all sort of bits that contain a description
of which FP8 subfeatures are implemented.

We don't really care about them, so let's just expose that register
and allow userspace to disable subfeatures at will.

Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 arch/arm64/kvm/sys_regs.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index 79d67f19130d..4c2f7c0af537 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -2386,7 +2386,7 @@ static const struct sys_reg_desc sys_reg_descs[] = {
 	ID_WRITABLE(ID_AA64ZFR0_EL1, ~ID_AA64ZFR0_EL1_RES0),
 	ID_HIDDEN(ID_AA64SMFR0_EL1),
 	ID_UNALLOCATED(4,6),
-	ID_UNALLOCATED(4,7),
+	ID_WRITABLE(ID_AA64FPFR0_EL1, ~ID_AA64FPFR0_EL1_RES0),
 
 	/* CRm=5 */
 	{ SYS_DESC(SYS_ID_AA64DFR0_EL1),
-- 
2.39.2

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