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| author | Marc Zyngier <maz@kernel.org> | 2026-01-08 20:32:32 +0300 |
|---|---|---|
| committer | Marc Zyngier <maz@kernel.org> | 2026-01-15 14:58:57 +0300 |
| commit | 592dc2c020686536dae1c427c78cf558a3df4414 (patch) | |
| tree | 7543af865dde48335adc70e0e618b027b044355c | |
| parent | e5d40a5a97c1d57e89aa5f324734065c6580b436 (diff) | |
| download | linux-592dc2c020686536dae1c427c78cf558a3df4414.tar.xz | |
KVM: arm64: pkvm: Report optional ID register traps with a 0x18 syndrome
With FEAT_IDST, unimplemented system registers in the feature ID space
must be reported using EC=0x18 at the closest handling EL, rather than
with an UNDEF.
Most of these system registers are always implemented thanks to their
dependency on FEAT_AA64, except for a set of (currently) three registers:
GMID_EL1 (depending on MTE2), CCSIDR2_EL1 (depending on FEAT_CCIDX),
and SMIDR_EL1 (depending on SME).
For these three registers, report their trap as EC=0x18 if they
end-up trapping into KVM and that FEAT_IDST is implemented in the guest.
Otherwise, just make them UNDEF.
Link: https://patch.msgid.link/20260108173233.2911955-9-maz@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
| -rw-r--r-- | arch/arm64/kvm/hyp/nvhe/sys_regs.c | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/arch/arm64/kvm/hyp/nvhe/sys_regs.c b/arch/arm64/kvm/hyp/nvhe/sys_regs.c index b197f3eb272c..06d28621722e 100644 --- a/arch/arm64/kvm/hyp/nvhe/sys_regs.c +++ b/arch/arm64/kvm/hyp/nvhe/sys_regs.c @@ -347,6 +347,18 @@ static bool pvm_gic_read_sre(struct kvm_vcpu *vcpu, return true; } +static bool pvm_idst_access(struct kvm_vcpu *vcpu, + struct sys_reg_params *p, + const struct sys_reg_desc *r) +{ + if (kvm_has_feat(vcpu->kvm, ID_AA64MMFR2_EL1, IDS, IMP)) + inject_sync64(vcpu, kvm_vcpu_get_esr(vcpu)); + else + inject_undef64(vcpu); + + return false; +} + /* Mark the specified system register as an AArch32 feature id register. */ #define AARCH32(REG) { SYS_DESC(REG), .access = pvm_access_id_aarch32 } @@ -477,6 +489,9 @@ static const struct sys_reg_desc pvm_sys_reg_descs[] = { HOST_HANDLED(SYS_CCSIDR_EL1), HOST_HANDLED(SYS_CLIDR_EL1), + { SYS_DESC(SYS_CCSIDR2_EL1), .access = pvm_idst_access }, + { SYS_DESC(SYS_GMID_EL1), .access = pvm_idst_access }, + { SYS_DESC(SYS_SMIDR_EL1), .access = pvm_idst_access }, HOST_HANDLED(SYS_AIDR_EL1), HOST_HANDLED(SYS_CSSELR_EL1), HOST_HANDLED(SYS_CTR_EL0), |