From: Will Deacon <[email protected]> 3.12-stable review patch. If anyone has any objections, please let me know.
=============== commit 63afbe7a0ac184ef8485dac4914e87b211b5bfaa upstream. 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 <[email protected]> Cc: Marc Zyngier <[email protected]> Cc: Gleb Natapov <[email protected]> Cc: Paolo Bonzini <[email protected]> Cc: Joel Schopp <[email protected]> Cc: Don Dutile <[email protected]> Acked-by: Peter Maydell <[email protected]> Acked-by: Joel Schopp <[email protected]> Acked-by: Marc Zyngier <[email protected]> Signed-off-by: Will Deacon <[email protected]> Signed-off-by: Christoffer Dall <[email protected]> Signed-off-by: Shannon Zhao <[email protected]> Signed-off-by: Jiri Slaby <[email protected]> --- virt/kvm/arm/vgic.c | 24 ++++++++++++++++++++---- 1 file changed, 20 insertions(+), 4 deletions(-) diff --git a/virt/kvm/arm/vgic.c b/virt/kvm/arm/vgic.c index 46221c99334f..7ee14f0d4fb3 100644 --- a/virt/kvm/arm/vgic.c +++ b/virt/kvm/arm/vgic.c @@ -1365,17 +1365,33 @@ 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: -- 2.3.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
