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authorOliver Upton <oliver.upton@linux.dev>2025-03-19 14:54:32 -0700
committerOliver Upton <oliver.upton@linux.dev>2025-03-19 14:54:32 -0700
commit4f2774c57a3e87e40b1cd7074e1a564847e39e4f (patch)
tree78e84318bd5141ec69d4eae22f7a860d2aa496bb /arch/arm64/include
parent1b1d1b17b8775f58215b166e24d931890682608e (diff)
parent5980a693701229c02f19fec051ae0845309413c6 (diff)
Merge branch 'kvm-arm64/writable-midr' into kvmarm/next
* kvm-arm64/writable-midr: : Writable implementation ID registers, courtesy of Sebastian Ott : : Introduce a new capability that allows userspace to set the : ID registers that identify a CPU implementation: MIDR_EL1, REVIDR_EL1, : and AIDR_EL1. Also plug a hole in KVM's trap configuration where : SMIDR_EL1 was readable at EL1, despite the fact that KVM does not : support SME. KVM: arm64: Fix documentation for KVM_CAP_ARM_WRITABLE_IMP_ID_REGS KVM: arm64: Copy MIDR_EL1 into hyp VM when it is writable KVM: arm64: Copy guest CTR_EL0 into hyp VM KVM: selftests: arm64: Test writes to MIDR,REVIDR,AIDR KVM: arm64: Allow userspace to change the implementation ID registers KVM: arm64: Load VPIDR_EL2 with the VM's MIDR_EL1 value KVM: arm64: Maintain per-VM copy of implementation ID regs KVM: arm64: Set HCR_EL2.TID1 unconditionally Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
Diffstat (limited to 'arch/arm64/include')
-rw-r--r--arch/arm64/include/asm/kvm_arm.h4
-rw-r--r--arch/arm64/include/asm/kvm_host.h11
2 files changed, 13 insertions, 2 deletions
diff --git a/arch/arm64/include/asm/kvm_arm.h b/arch/arm64/include/asm/kvm_arm.h
index c2417a424b98..974d72b5905b 100644
--- a/arch/arm64/include/asm/kvm_arm.h
+++ b/arch/arm64/include/asm/kvm_arm.h
@@ -92,12 +92,12 @@
* SWIO: Turn set/way invalidates into set/way clean+invalidate
* PTW: Take a stage2 fault if a stage1 walk steps in device memory
* TID3: Trap EL1 reads of group 3 ID registers
- * TID2: Trap CTR_EL0, CCSIDR2_EL1, CLIDR_EL1, and CSSELR_EL1
+ * TID1: Trap REVIDR_EL1, AIDR_EL1, and SMIDR_EL1
*/
#define HCR_GUEST_FLAGS (HCR_TSC | HCR_TSW | HCR_TWE | HCR_TWI | HCR_VM | \
HCR_BSU_IS | HCR_FB | HCR_TACR | \
HCR_AMO | HCR_SWIO | HCR_TIDCP | HCR_RW | HCR_TLOR | \
- HCR_FMO | HCR_IMO | HCR_PTW | HCR_TID3)
+ HCR_FMO | HCR_IMO | HCR_PTW | HCR_TID3 | HCR_TID1)
#define HCR_HOST_NVHE_FLAGS (HCR_RW | HCR_API | HCR_APK | HCR_ATA)
#define HCR_HOST_NVHE_PROTECTED_FLAGS (HCR_HOST_NVHE_FLAGS | HCR_TSC)
#define HCR_HOST_VHE_FLAGS (HCR_RW | HCR_TGE | HCR_E2H)
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 34c43af8b7b7..f49b680e032d 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -336,6 +336,8 @@ struct kvm_arch {
#define KVM_ARCH_FLAG_FGU_INITIALIZED 8
/* SVE exposed to guest */
#define KVM_ARCH_FLAG_GUEST_HAS_SVE 9
+ /* MIDR_EL1, REVIDR_EL1, and AIDR_EL1 are writable from userspace */
+#define KVM_ARCH_FLAG_WRITABLE_IMP_ID_REGS 10
unsigned long flags;
/* VM-wide vCPU feature set */
@@ -375,6 +377,9 @@ struct kvm_arch {
#define KVM_ARM_ID_REG_NUM (IDREG_IDX(sys_reg(3, 0, 0, 7, 7)) + 1)
u64 id_regs[KVM_ARM_ID_REG_NUM];
+ u64 midr_el1;
+ u64 revidr_el1;
+ u64 aidr_el1;
u64 ctr_el0;
/* Masks for VNCR-backed and general EL2 sysregs */
@@ -1489,6 +1494,12 @@ static inline u64 *__vm_id_reg(struct kvm_arch *ka, u32 reg)
return &ka->id_regs[IDREG_IDX(reg)];
case SYS_CTR_EL0:
return &ka->ctr_el0;
+ case SYS_MIDR_EL1:
+ return &ka->midr_el1;
+ case SYS_REVIDR_EL1:
+ return &ka->revidr_el1;
+ case SYS_AIDR_EL1:
+ return &ka->aidr_el1;
default:
WARN_ON_ONCE(1);
return NULL;