From ac97249c863bcacf17a7626659caedf7a34d518b Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Fri, 21 Jan 2022 21:07:47 +0000 Subject: [PATCH] UPSTREAM: KVM: arm64: vgic-v3: Restrict SEIS workaround to known broken systems Contrary to what df652bcf1136 ("KVM: arm64: vgic-v3: Work around GICv3 locally generated SErrors") was asserting, there is at least one other system out there (Cavium ThunderX2) implementing SEIS, and not in an obviously broken way. So instead of imposing the M1 workaround on an innocent bystander, let's limit it to the two known broken Apple implementations. Fixes: df652bcf1136 ("KVM: arm64: vgic-v3: Work around GICv3 locally generated SErrors") Reported-by: Ard Biesheuvel Tested-by: Ard Biesheuvel Acked-by: Ard Biesheuvel Signed-off-by: Marc Zyngier Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20220122103912.795026-1-maz@kernel.org (cherry picked from commit d11a327ed95dbec756b99cbfef2a7fd85c9eeb09) Signed-off-by: Will Deacon Bug: 233587962 Bug: 233588291 Change-Id: I4c1b8faab30744f81b012e03b31cdd8254614f87 --- arch/arm64/kvm/hyp/vgic-v3-sr.c | 3 +++ arch/arm64/kvm/vgic/vgic-v3.c | 17 +++++++++++++++-- 2 files changed, 18 insertions(+), 2 deletions(-) diff --git a/arch/arm64/kvm/hyp/vgic-v3-sr.c b/arch/arm64/kvm/hyp/vgic-v3-sr.c index 20db2f281cf2..4fb419f7b8b6 100644 --- a/arch/arm64/kvm/hyp/vgic-v3-sr.c +++ b/arch/arm64/kvm/hyp/vgic-v3-sr.c @@ -983,6 +983,9 @@ static void __vgic_v3_read_ctlr(struct kvm_vcpu *vcpu, u32 vmcr, int rt) val = ((vtr >> 29) & 7) << ICC_CTLR_EL1_PRI_BITS_SHIFT; /* IDbits */ val |= ((vtr >> 23) & 7) << ICC_CTLR_EL1_ID_BITS_SHIFT; + /* SEIS */ + if (kvm_vgic_global_state.ich_vtr_el2 & ICH_VTR_SEIS_MASK) + val |= BIT(ICC_CTLR_EL1_SEIS_SHIFT); /* A3V */ val |= ((vtr >> 21) & 1) << ICC_CTLR_EL1_A3V_SHIFT; /* EOImode */ diff --git a/arch/arm64/kvm/vgic/vgic-v3.c b/arch/arm64/kvm/vgic/vgic-v3.c index 78cf674c1230..221489c29354 100644 --- a/arch/arm64/kvm/vgic/vgic-v3.c +++ b/arch/arm64/kvm/vgic/vgic-v3.c @@ -609,6 +609,18 @@ static int __init early_gicv4_enable(char *buf) } early_param("kvm-arm.vgic_v4_enable", early_gicv4_enable); +static const struct midr_range broken_seis[] = { + MIDR_ALL_VERSIONS(MIDR_APPLE_M1_ICESTORM), + MIDR_ALL_VERSIONS(MIDR_APPLE_M1_FIRESTORM), + {}, +}; + +static bool vgic_v3_broken_seis(void) +{ + return ((kvm_vgic_global_state.ich_vtr_el2 & ICH_VTR_SEIS_MASK) && + is_midr_in_range_list(read_cpuid_id(), broken_seis)); +} + /** * vgic_v3_probe - probe for a VGICv3 compatible interrupt controller * @info: pointer to the GIC description @@ -676,9 +688,10 @@ int vgic_v3_probe(const struct gic_kvm_info *info) group1_trap = true; } - if (kvm_vgic_global_state.ich_vtr_el2 & ICH_VTR_SEIS_MASK) { - kvm_info("GICv3 with locally generated SEI\n"); + if (vgic_v3_broken_seis()) { + kvm_info("GICv3 with broken locally generated SEI\n"); + kvm_vgic_global_state.ich_vtr_el2 &= ~ICH_VTR_SEIS_MASK; group0_trap = true; group1_trap = true; if (ich_vtr_el2 & ICH_VTR_TDS_MASK)