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| author | Marc Zyngier <maz@kernel.org> | 2021-03-05 18:52:53 +0000 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2021-03-06 04:18:41 -0500 |
| commit | 9739f6ef053f104a997165701c6e15582c4307ee (patch) | |
| tree | 9d587b064d86e522cce5ffb4cdb9183baf908fb4 /arch/arm64/kvm/vgic | |
| parent | b9d699e2694d032aa8ecc15141f698ccb050dc95 (diff) | |
| download | linux-9739f6ef053f104a997165701c6e15582c4307ee.tar.bz2 | |
KVM: arm64: Workaround firmware wrongly advertising GICv2-on-v3 compatibility
It looks like we have broken firmware out there that wrongly advertises
a GICv2 compatibility interface, despite the CPUs not being able to deal
with it.
To work around this, check that the CPU initialising KVM is actually able
to switch to MMIO instead of system registers, and use that as a
precondition to enable GICv2 compatibility in KVM.
Note that the detection happens on a single CPU. If the firmware is
lying *and* that the CPUs are asymetric, all hope is lost anyway.
Reported-by: Shameerali Kolothum Thodi <shameerali.kolothum.thodi@huawei.com>
Tested-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Message-Id: <20210305185254.3730990-8-maz@kernel.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/arm64/kvm/vgic')
| -rw-r--r-- | arch/arm64/kvm/vgic/vgic-v3.c | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/arch/arm64/kvm/vgic/vgic-v3.c b/arch/arm64/kvm/vgic/vgic-v3.c index c3e6c3fd333b..6f530925a231 100644 --- a/arch/arm64/kvm/vgic/vgic-v3.c +++ b/arch/arm64/kvm/vgic/vgic-v3.c @@ -575,8 +575,10 @@ early_param("kvm-arm.vgic_v4_enable", early_gicv4_enable); int vgic_v3_probe(const struct gic_kvm_info *info) { u64 ich_vtr_el2 = kvm_call_hyp_ret(__vgic_v3_get_gic_config); + bool has_v2; int ret; + has_v2 = ich_vtr_el2 >> 63; ich_vtr_el2 = (u32)ich_vtr_el2; /* @@ -596,13 +598,15 @@ int vgic_v3_probe(const struct gic_kvm_info *info) gicv4_enable ? "en" : "dis"); } + kvm_vgic_global_state.vcpu_base = 0; + if (!info->vcpu.start) { kvm_info("GICv3: no GICV resource entry\n"); - kvm_vgic_global_state.vcpu_base = 0; + } else if (!has_v2) { + pr_warn(FW_BUG "CPU interface incapable of MMIO access\n"); } else if (!PAGE_ALIGNED(info->vcpu.start)) { pr_warn("GICV physical address 0x%llx not page aligned\n", (unsigned long long)info->vcpu.start); - kvm_vgic_global_state.vcpu_base = 0; } else { kvm_vgic_global_state.vcpu_base = info->vcpu.start; kvm_vgic_global_state.can_emulate_gicv2 = true; |