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authorChristoffer Dall <christoffer.dall@arm.com>2018-07-16 16:06:24 +0300
committerMarc Zyngier <marc.zyngier@arm.com>2018-07-21 18:02:28 +0300
commitb489edc36169938e955c748eb83eb707bd53436e (patch)
tree8206bddd7cf6c7352f6dbd567521cec2ff56f71a
parentc6e0917b67fc006f3785b79bfdacdf9eef2f4816 (diff)
downloadlinux-b489edc36169938e955c748eb83eb707bd53436e.tar.xz
KVM: arm/arm64: vgic: Return error on incompatible uaccess GICD_IIDR writes
If userspace attempts to write a GICD_IIDR that does not match the kernel version, return an error to userspace. The intention is to allow implementation changes inside KVM while avoiding silently breaking migration resulting in guests not running without any clear indication of what went wrong. Reviewed-by: Andrew Jones <drjones@redhat.com> Signed-off-by: Christoffer Dall <christoffer.dall@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
-rw-r--r--virt/kvm/arm/vgic/vgic-mmio-v2.c21
-rw-r--r--virt/kvm/arm/vgic/vgic-mmio-v3.c21
2 files changed, 36 insertions, 6 deletions
diff --git a/virt/kvm/arm/vgic/vgic-mmio-v2.c b/virt/kvm/arm/vgic/vgic-mmio-v2.c
index db646f140e7d..4f0f2c4165ec 100644
--- a/virt/kvm/arm/vgic/vgic-mmio-v2.c
+++ b/virt/kvm/arm/vgic/vgic-mmio-v2.c
@@ -75,6 +75,20 @@ static void vgic_mmio_write_v2_misc(struct kvm_vcpu *vcpu,
}
}
+static int vgic_mmio_uaccess_write_v2_misc(struct kvm_vcpu *vcpu,
+ gpa_t addr, unsigned int len,
+ unsigned long val)
+{
+ switch (addr & 0x0c) {
+ case GIC_DIST_IIDR:
+ if (val != vgic_mmio_read_v2_misc(vcpu, addr, len))
+ return -EINVAL;
+ }
+
+ vgic_mmio_write_v2_misc(vcpu, addr, len, val);
+ return 0;
+}
+
static void vgic_mmio_write_sgir(struct kvm_vcpu *source_vcpu,
gpa_t addr, unsigned int len,
unsigned long val)
@@ -367,9 +381,10 @@ static void vgic_mmio_write_apr(struct kvm_vcpu *vcpu,
}
static const struct vgic_register_region vgic_v2_dist_registers[] = {
- REGISTER_DESC_WITH_LENGTH(GIC_DIST_CTRL,
- vgic_mmio_read_v2_misc, vgic_mmio_write_v2_misc, 12,
- VGIC_ACCESS_32bit),
+ REGISTER_DESC_WITH_LENGTH_UACCESS(GIC_DIST_CTRL,
+ vgic_mmio_read_v2_misc, vgic_mmio_write_v2_misc,
+ NULL, vgic_mmio_uaccess_write_v2_misc,
+ 12, VGIC_ACCESS_32bit),
REGISTER_DESC_WITH_BITS_PER_IRQ(GIC_DIST_IGROUP,
vgic_mmio_read_raz, vgic_mmio_write_wi, NULL, NULL, 1,
VGIC_ACCESS_32bit),
diff --git a/virt/kvm/arm/vgic/vgic-mmio-v3.c b/virt/kvm/arm/vgic/vgic-mmio-v3.c
index ef57a1aa0b14..abdb0ec77b38 100644
--- a/virt/kvm/arm/vgic/vgic-mmio-v3.c
+++ b/virt/kvm/arm/vgic/vgic-mmio-v3.c
@@ -113,6 +113,20 @@ static void vgic_mmio_write_v3_misc(struct kvm_vcpu *vcpu,
}
}
+static int vgic_mmio_uaccess_write_v3_misc(struct kvm_vcpu *vcpu,
+ gpa_t addr, unsigned int len,
+ unsigned long val)
+{
+ switch (addr & 0x0c) {
+ case GICD_IIDR:
+ if (val != vgic_mmio_read_v3_misc(vcpu, addr, len))
+ return -EINVAL;
+ }
+
+ vgic_mmio_write_v3_misc(vcpu, addr, len, val);
+ return 0;
+}
+
static unsigned long vgic_mmio_read_irouter(struct kvm_vcpu *vcpu,
gpa_t addr, unsigned int len)
{
@@ -449,9 +463,10 @@ static void vgic_mmio_write_pendbase(struct kvm_vcpu *vcpu,
}
static const struct vgic_register_region vgic_v3_dist_registers[] = {
- REGISTER_DESC_WITH_LENGTH(GICD_CTLR,
- vgic_mmio_read_v3_misc, vgic_mmio_write_v3_misc, 16,
- VGIC_ACCESS_32bit),
+ REGISTER_DESC_WITH_LENGTH_UACCESS(GICD_CTLR,
+ vgic_mmio_read_v3_misc, vgic_mmio_write_v3_misc,
+ NULL, vgic_mmio_uaccess_write_v3_misc,
+ 16, VGIC_ACCESS_32bit),
REGISTER_DESC_WITH_LENGTH(GICD_STATUSR,
vgic_mmio_read_rao, vgic_mmio_write_wi, 4,
VGIC_ACCESS_32bit),