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author | Christoffer Dall <christoffer.dall@linaro.org> | 2016-04-25 01:11:37 +0200 |
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committer | Christoffer Dall <christoffer.dall@linaro.org> | 2016-05-20 15:40:03 +0200 |
commit | c3199f28e09496aa9fec9313b4f6e90e7dc913f0 (patch) | |
tree | bbb54334faac81960f6dc872bde72d2b8e4bd725 /virt/kvm/arm/vgic/vgic-mmio-v2.c | |
parent | f94591e2e6fdca6e9a2cbf23e36a8803b4f605fe (diff) | |
download | linux-stable-c3199f28e09496aa9fec9313b4f6e90e7dc913f0.tar.gz linux-stable-c3199f28e09496aa9fec9313b4f6e90e7dc913f0.tar.bz2 linux-stable-c3199f28e09496aa9fec9313b4f6e90e7dc913f0.zip |
KVM: arm/arm64: vgic-new: Export register access interface
Userland can access the emulated GIC to save and restore its state
for initialization or migration purposes.
The kvm_io_bus API requires an absolute gpa, which does not fit the
KVM_DEV_ARM_VGIC_GRP_DIST_REGS user API, that only provides relative
offsets. So we provide a wrapper to plug into our MMIO framework and
find the respective register handler.
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Diffstat (limited to 'virt/kvm/arm/vgic/vgic-mmio-v2.c')
-rw-r--r-- | virt/kvm/arm/vgic/vgic-mmio-v2.c | 36 |
1 files changed, 36 insertions, 0 deletions
diff --git a/virt/kvm/arm/vgic/vgic-mmio-v2.c b/virt/kvm/arm/vgic/vgic-mmio-v2.c index 71896900ad12..a25512212bc7 100644 --- a/virt/kvm/arm/vgic/vgic-mmio-v2.c +++ b/virt/kvm/arm/vgic/vgic-mmio-v2.c @@ -296,3 +296,39 @@ int vgic_v2_has_attr_regs(struct kvm_device *dev, struct kvm_device_attr *attr) return -ENXIO; } + +/* + * When userland tries to access the VGIC register handlers, we need to + * create a usable struct vgic_io_device to be passed to the handlers and we + * have to set up a buffer similar to what would have happened if a guest MMIO + * access occurred, including doing endian conversions on BE systems. + */ +static int vgic_uaccess(struct kvm_vcpu *vcpu, struct vgic_io_device *dev, + bool is_write, int offset, u32 *val) +{ + unsigned int len = 4; + u8 buf[4]; + int ret; + + if (is_write) { + vgic_data_host_to_mmio_bus(buf, len, *val); + ret = kvm_io_gic_ops.write(vcpu, &dev->dev, offset, len, buf); + } else { + ret = kvm_io_gic_ops.read(vcpu, &dev->dev, offset, len, buf); + if (!ret) + *val = vgic_data_mmio_bus_to_host(buf, len); + } + + return ret; +} + +int vgic_v2_dist_uaccess(struct kvm_vcpu *vcpu, bool is_write, + int offset, u32 *val) +{ + struct vgic_io_device dev = { + .regions = vgic_v2_dist_registers, + .nr_regions = ARRAY_SIZE(vgic_v2_dist_registers), + }; + + return vgic_uaccess(vcpu, &dev, is_write, offset, val); +} |