From: Christoffer Dall <cdall@linaro.org>
To: Marc Zyngier <marc.zyngier@arm.com>
Cc: kvm@vger.kernel.org, David Daney <david.daney@cavium.com>,
Catalin Marinas <catalin.marinas@arm.com>,
Robert Richter <rrichter@cavium.com>,
linux-arm-kernel@lists.infradead.org,
kvmarm@lists.cs.columbia.edu
Subject: Re: [PATCH v3 26/27] KVM: arm64: Log an error if trapping a read-from-write-only GICv3 access
Date: Fri, 9 Jun 2017 17:33:06 +0200 [thread overview]
Message-ID: <20170609153306.GH11099@cbox> (raw)
In-Reply-To: <20170609114956.25963-27-marc.zyngier@arm.com>
On Fri, Jun 09, 2017 at 12:49:55PM +0100, Marc Zyngier wrote:
> A read-from-write-only GICv3 access should UNDEF at EL1. But since
> we're in complete paranoia-land with broken CPUs, let's assume the
> worse and gracefully handle the case.
>
> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Christoffer Dall <cdall@linaro.org>
> ---
> arch/arm64/kvm/sys_regs.c | 12 ++++++++----
> virt/kvm/arm/hyp/vgic-v3-sr.c | 4 ++++
> 2 files changed, 12 insertions(+), 4 deletions(-)
>
> diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
> index 0fe27024a2e1..8d51c075966d 100644
> --- a/arch/arm64/kvm/sys_regs.c
> +++ b/arch/arm64/kvm/sys_regs.c
> @@ -56,7 +56,8 @@
> */
>
> static bool read_from_write_only(struct kvm_vcpu *vcpu,
> - const struct sys_reg_params *params)
> + struct sys_reg_params *params,
> + const struct sys_reg_desc *r)
> {
> WARN_ONCE(1, "Unexpected sys_reg read to write-only register\n");
> print_sys_reg_instr(params);
> @@ -93,7 +94,7 @@ static bool access_dcsw(struct kvm_vcpu *vcpu,
> const struct sys_reg_desc *r)
> {
> if (!p->is_write)
> - return read_from_write_only(vcpu, p);
> + return read_from_write_only(vcpu, p, r);
>
> kvm_set_way_flush(vcpu);
> return true;
> @@ -135,7 +136,7 @@ static bool access_gic_sgi(struct kvm_vcpu *vcpu,
> const struct sys_reg_desc *r)
> {
> if (!p->is_write)
> - return read_from_write_only(vcpu, p);
> + return read_from_write_only(vcpu, p, r);
>
> vgic_v3_dispatch_sgi(vcpu, p->regval);
>
> @@ -773,7 +774,7 @@ static bool access_pmswinc(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
> return trap_raz_wi(vcpu, p, r);
>
> if (!p->is_write)
> - return read_from_write_only(vcpu, p);
> + return read_from_write_only(vcpu, p, r);
>
> if (pmu_write_swinc_el0_disabled(vcpu))
> return false;
> @@ -953,7 +954,10 @@ static const struct sys_reg_desc sys_reg_descs[] = {
>
> { SYS_DESC(SYS_VBAR_EL1), NULL, reset_val, VBAR_EL1, 0 },
>
> + { SYS_DESC(SYS_ICC_EOIR0_EL1), read_from_write_only },
> + { SYS_DESC(SYS_ICC_DIR_EL1), read_from_write_only },
> { SYS_DESC(SYS_ICC_SGI1R_EL1), access_gic_sgi },
> + { SYS_DESC(SYS_ICC_EOIR1_EL1), read_from_write_only },
> { SYS_DESC(SYS_ICC_SRE_EL1), access_gic_sre },
>
> { SYS_DESC(SYS_CONTEXTIDR_EL1), access_vm_reg, reset_val, CONTEXTIDR_EL1, 0 },
> diff --git a/virt/kvm/arm/hyp/vgic-v3-sr.c b/virt/kvm/arm/hyp/vgic-v3-sr.c
> index 15b557697086..b26ce58b012a 100644
> --- a/virt/kvm/arm/hyp/vgic-v3-sr.c
> +++ b/virt/kvm/arm/hyp/vgic-v3-sr.c
> @@ -980,6 +980,8 @@ int __hyp_text __vgic_v3_perform_cpuif_access(struct kvm_vcpu *vcpu)
> break;
> case SYS_ICC_EOIR0_EL1:
> case SYS_ICC_EOIR1_EL1:
> + if (unlikely(is_read))
> + return 0;
> fn = __vgic_v3_write_eoir;
> break;
> case SYS_ICC_GRPEN1_EL1:
> @@ -1039,6 +1041,8 @@ int __hyp_text __vgic_v3_perform_cpuif_access(struct kvm_vcpu *vcpu)
> fn = __vgic_v3_write_bpr0;
> break;
> case SYS_ICC_DIR_EL1:
> + if (unlikely(is_read))
> + return 0;
> fn = __vgic_v3_write_dir;
> break;
> case SYS_ICC_RPR_EL1:
> --
> 2.11.0
>
next prev parent reply other threads:[~2017-06-09 15:33 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-06-09 11:49 [PATCH v3 00/27] arm64: KVM: Mediate access to GICv3 sysregs at EL2 Marc Zyngier
2017-06-09 11:49 ` [PATCH v3 01/27] arm64: Add a facility to turn an ESR syndrome into a sysreg encoding Marc Zyngier
2017-06-09 11:49 ` [PATCH v3 02/27] KVM: arm/arm64: vgic-v3: Add accessors for the ICH_APxRn_EL2 registers Marc Zyngier
2017-06-09 11:49 ` [PATCH v3 03/27] KVM: arm64: Make kvm_condition_valid32() accessible from EL2 Marc Zyngier
2017-06-09 11:49 ` [PATCH v3 04/27] KVM: arm64: vgic-v3: Add hook to handle guest GICv3 sysreg accesses at EL2 Marc Zyngier
2017-06-09 11:49 ` [PATCH v3 05/27] KVM: arm64: vgic-v3: Add ICV_BPR1_EL1 handler Marc Zyngier
2017-06-09 15:23 ` Christoffer Dall
2017-06-09 11:49 ` [PATCH v3 06/27] KVM: arm64: vgic-v3: Add ICV_IGRPEN1_EL1 handler Marc Zyngier
2017-06-09 11:49 ` [PATCH v3 07/27] KVM: arm64: vgic-v3: Add ICV_IAR1_EL1 handler Marc Zyngier
2017-06-09 15:26 ` Christoffer Dall
2017-06-09 11:49 ` [PATCH v3 08/27] KVM: arm64: vgic-v3: Add ICV_EOIR1_EL1 handler Marc Zyngier
2017-06-09 15:27 ` Christoffer Dall
2017-06-09 11:49 ` [PATCH v3 09/27] KVM: arm64: vgic-v3: Add ICV_AP1Rn_EL1 handler Marc Zyngier
2017-06-09 11:49 ` [PATCH v3 10/27] KVM: arm64: vgic-v3: Add ICV_HPPIR1_EL1 handler Marc Zyngier
2017-06-09 15:28 ` Christoffer Dall
2017-06-09 11:49 ` [PATCH v3 11/27] KVM: arm64: vgic-v3: Enable trapping of Group-1 system registers Marc Zyngier
2017-06-09 11:49 ` [PATCH v3 12/27] KVM: arm64: Enable GICv3 Group-1 sysreg trapping via command-line Marc Zyngier
2017-06-09 15:29 ` Christoffer Dall
2017-06-09 11:49 ` [PATCH v3 13/27] KVM: arm64: vgic-v3: Add ICV_BPR0_EL1 handler Marc Zyngier
2017-06-09 15:29 ` Christoffer Dall
2017-06-09 11:49 ` [PATCH v3 14/27] KVM: arm64: vgic-v3: Add ICV_IGNREN0_EL1 handler Marc Zyngier
2017-06-09 11:49 ` [PATCH v3 15/27] KVM: arm64: vgic-v3: Add misc Group-0 handlers Marc Zyngier
2017-06-09 11:49 ` [PATCH v3 16/27] KVM: arm64: vgic-v3: Enable trapping of Group-0 system registers Marc Zyngier
2017-06-09 11:49 ` [PATCH v3 17/27] KVM: arm64: Enable GICv3 Group-0 sysreg trapping via command-line Marc Zyngier
2017-06-09 11:49 ` [PATCH v3 18/27] arm64: Add MIDR values for Cavium cn83XX SoCs Marc Zyngier
2017-06-09 11:49 ` [PATCH v3 19/27] arm64: Add workaround for Cavium Thunder erratum 30115 Marc Zyngier
2017-06-09 11:49 ` [PATCH v3 20/27] KVM: arm64: vgic-v3: Add ICV_DIR_EL1 handler Marc Zyngier
2017-06-09 11:49 ` [PATCH v3 21/27] KVM: arm64: vgic-v3: Add ICV_RPR_EL1 handler Marc Zyngier
2017-06-09 11:49 ` [PATCH v3 22/27] KVM: arm64: vgic-v3: Add ICV_CTLR_EL1 handler Marc Zyngier
2017-06-09 11:49 ` [PATCH v3 23/27] KVM: arm64: vgic-v3: Add ICV_PMR_EL1 handler Marc Zyngier
2017-06-09 11:49 ` [PATCH v3 24/27] KVM: arm64: Enable GICv3 common sysreg trapping via command-line Marc Zyngier
2017-06-09 15:31 ` Christoffer Dall
2017-06-09 11:49 ` [PATCH v3 25/27] KVM: arm64: vgic-v3: Log which GICv3 system registers are trapped Marc Zyngier
2017-06-09 11:49 ` [PATCH v3 26/27] KVM: arm64: Log an error if trapping a read-from-write-only GICv3 access Marc Zyngier
2017-06-09 15:33 ` Christoffer Dall [this message]
2017-06-09 11:49 ` [PATCH v3 27/27] KVM: arm64: Log an error if trapping a write-to-read-only " Marc Zyngier
2017-06-09 15:34 ` Christoffer Dall
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