* [PATCH] KVM: arm64: vgic-v3: Restrict SEIS workaround to known broken systems
@ 2022-01-22 10:39 Marc Zyngier
2022-01-22 11:14 ` Ard Biesheuvel
0 siblings, 1 reply; 3+ messages in thread
From: Marc Zyngier @ 2022-01-22 10:39 UTC (permalink / raw)
To: linux-arm-kernel, kvmarm, kvm
Cc: James Morse, Suzuki K Poulose, Alexandru Elisei, kernel-team,
Ard Biesheuvel
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 <ardb@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
---
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..d34a795f730c 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 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)
--
2.34.1
^ permalink raw reply related [flat|nested] 3+ messages in thread* Re: [PATCH] KVM: arm64: vgic-v3: Restrict SEIS workaround to known broken systems
2022-01-22 10:39 [PATCH] KVM: arm64: vgic-v3: Restrict SEIS workaround to known broken systems Marc Zyngier
@ 2022-01-22 11:14 ` Ard Biesheuvel
2022-01-22 11:32 ` Marc Zyngier
0 siblings, 1 reply; 3+ messages in thread
From: Ard Biesheuvel @ 2022-01-22 11:14 UTC (permalink / raw)
To: Marc Zyngier
Cc: Linux ARM, kvmarm, kvm, James Morse, Suzuki K Poulose,
Alexandru Elisei, Android Kernel Team
On Sat, 22 Jan 2022 at 11:39, Marc Zyngier <maz@kernel.org> wrote:
>
> 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 <ardb@kernel.org>
> Signed-off-by: Marc Zyngier <maz@kernel.org>
Thanks for the fix.
Tested-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
One nit below.
> ---
> 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..d34a795f730c 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 struct midr_range broken_seis[] = {
Can this be const?
> + 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)
> --
> 2.34.1
>
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: [PATCH] KVM: arm64: vgic-v3: Restrict SEIS workaround to known broken systems
2022-01-22 11:14 ` Ard Biesheuvel
@ 2022-01-22 11:32 ` Marc Zyngier
0 siblings, 0 replies; 3+ messages in thread
From: Marc Zyngier @ 2022-01-22 11:32 UTC (permalink / raw)
To: Ard Biesheuvel
Cc: Linux ARM, kvmarm, kvm, James Morse, Suzuki K Poulose,
Alexandru Elisei, Android Kernel Team
On 2022-01-22 11:14, Ard Biesheuvel wrote:
> On Sat, 22 Jan 2022 at 11:39, Marc Zyngier <maz@kernel.org> wrote:
>>
>> 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 <ardb@kernel.org>
>> Signed-off-by: Marc Zyngier <maz@kernel.org>
>
> Thanks for the fix.
>
> Tested-by: Ard Biesheuvel <ardb@kernel.org>
> Acked-by: Ard Biesheuvel <ardb@kernel.org>
Thanks for that.
>
> One nit below.
>
>> ---
>> 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..d34a795f730c 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 struct midr_range broken_seis[] = {
>
> Can this be const?
Absolutely. I'll fold that in.
Thanks,
M.
--
Jazz is not dead. It just smells funny...
^ permalink raw reply [flat|nested] 3+ messages in thread
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2022-01-22 10:39 [PATCH] KVM: arm64: vgic-v3: Restrict SEIS workaround to known broken systems Marc Zyngier
2022-01-22 11:14 ` Ard Biesheuvel
2022-01-22 11:32 ` Marc Zyngier
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