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authorWill Deacon <will.deacon@arm.com>2014-07-25 16:29:12 +0100
committerChristoffer Dall <christoffer.dall@linaro.org>2014-07-30 14:35:42 +0200
commit63afbe7a0ac184ef8485dac4914e87b211b5bfaa (patch)
tree509e8c6d474365222b5d7c21779e6a0688e3a3ac
parentbb18b526a9d8d4a3fe56f234d5013b9f6036978d (diff)
downloadlinux-63afbe7a0ac184ef8485dac4914e87b211b5bfaa.tar.gz
kvm: arm64: vgic: fix hyp panic with 64k pages on juno platform
If the physical address of GICV isn't page-aligned, then we end up creating a stage-2 mapping of the page containing it, which causes us to map neighbouring memory locations directly into the guest. As an example, consider a platform with GICV at physical 0x2c02f000 running a 64k-page host kernel. If qemu maps this into the guest at 0x80010000, then guest physical addresses 0x80010000 - 0x8001efff will map host physical region 0x2c020000 - 0x2c02efff. Accesses to these physical regions may cause UNPREDICTABLE behaviour, for example, on the Juno platform this will cause an SError exception to EL3, which brings down the entire physical CPU resulting in RCU stalls / HYP panics / host crashing / wasted weeks of debugging. SBSA recommends that systems alias the 4k GICV across the bounding 64k region, in which case GICV physical could be described as 0x2c020000 in the above scenario. This patch fixes the problem by failing the vgic probe if the physical base address or the size of GICV aren't page-aligned. Note that this generated a warning in dmesg about freeing enabled IRQs, so I had to move the IRQ enabling later in the probe. Cc: Christoffer Dall <christoffer.dall@linaro.org> Cc: Marc Zyngier <marc.zyngier@arm.com> Cc: Gleb Natapov <gleb@kernel.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Joel Schopp <joel.schopp@amd.com> Cc: Don Dutile <ddutile@redhat.com> Acked-by: Peter Maydell <peter.maydell@linaro.org> Acked-by: Joel Schopp <joel.schopp@amd.com> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
-rw-r--r--virt/kvm/arm/vgic.c24
1 files changed, 20 insertions, 4 deletions
diff --git a/virt/kvm/arm/vgic.c b/virt/kvm/arm/vgic.c
index 56ff9bebb57..476d3bf540a 100644
--- a/virt/kvm/arm/vgic.c
+++ b/virt/kvm/arm/vgic.c
@@ -1526,17 +1526,33 @@ int kvm_vgic_hyp_init(void)
goto out_unmap;
}
- kvm_info("%s@%llx IRQ%d\n", vgic_node->name,
- vctrl_res.start, vgic_maint_irq);
- on_each_cpu(vgic_init_maintenance_interrupt, NULL, 1);
-
if (of_address_to_resource(vgic_node, 3, &vcpu_res)) {
kvm_err("Cannot obtain VCPU resource\n");
ret = -ENXIO;
goto out_unmap;
}
+
+ if (!PAGE_ALIGNED(vcpu_res.start)) {
+ kvm_err("GICV physical address 0x%llx not page aligned\n",
+ (unsigned long long)vcpu_res.start);
+ ret = -ENXIO;
+ goto out_unmap;
+ }
+
+ if (!PAGE_ALIGNED(resource_size(&vcpu_res))) {
+ kvm_err("GICV size 0x%llx not a multiple of page size 0x%lx\n",
+ (unsigned long long)resource_size(&vcpu_res),
+ PAGE_SIZE);
+ ret = -ENXIO;
+ goto out_unmap;
+ }
+
vgic_vcpu_base = vcpu_res.start;
+ kvm_info("%s@%llx IRQ%d\n", vgic_node->name,
+ vctrl_res.start, vgic_maint_irq);
+ on_each_cpu(vgic_init_maintenance_interrupt, NULL, 1);
+
goto out;
out_unmap: