The access is done similar to vGICv2, using KVM_DEV_ARM_VGIC_GRP_DIST_REGS
and KVM_DEV_ARM_VGIC_GRP_REDIST_REGS with KVM_SET_DEVICE_ATTR and
KVM_GET_DEVICE_ATTR ioctls. Since GICv3 can handle large number of CPUs,
KVM_DEV_ARM_VGIC_CPUID_MASK has been extended to 20 bits. This is enough
for 1048576 CPUs.
Some registers are 64-bit wide according to the specification.
KVM_DEV_ARM_VGIC_64BIT flag is introduced, allowing to perform full 64-bit
accesses.
Signed-off-by: Pavel Fedin <p.fedin@xxxxxxxxxxx>
---
Documentation/virtual/kvm/devices/arm-vgic.txt | 35 ++++++++--
arch/arm64/include/uapi/asm/kvm.h | 4 +-
virt/kvm/arm/vgic-v3-emul.c | 95 ++++++++++++++++++++++----
virt/kvm/arm/vgic.c | 1 +
4 files changed, 116 insertions(+), 19 deletions(-)
diff --git a/Documentation/virtual/kvm/devices/arm-vgic.txt b/Documentation/virtual/kvm/devices/arm-vgic.txt
index 3fb9054..03f640f 100644
--- a/Documentation/virtual/kvm/devices/arm-vgic.txt
+++ b/Documentation/virtual/kvm/devices/arm-vgic.txt
@@ -43,10 +43,13 @@ Groups:
KVM_DEV_ARM_VGIC_GRP_DIST_REGS
Attributes:
The attr field of kvm_device_attr encodes two values:
- bits: | 63 .... 40 | 39 .. 32 | 31 .... 0 |
- values: | reserved | cpu id | offset |
+ bits: | 63 | 62 .. 52 | 51 .. 32 | 31 .... 0 |
+ values: | size | reserved | cpu id | offset |
All distributor regs are (rw, 32-bit)
+ For GICv3 some regs are also (rw, 64-bit) according to the specification.
+ In order to perform full 64-bit access 'size' bit should be set to 1.
+ KVM_DEV_ARM_VGIC_64BIT flag value is provided for this purpose.
The offset is relative to the "Distributor base address" as defined in the
GICv2 specs. Getting or setting such a register has the same effect as
@@ -54,9 +57,33 @@ Groups:
specified with cpu id field. Note that most distributor fields are not
banked, but return the same value regardless of the cpu id used to access
the register.
+
+ Limitations:
+ - Priorities are not implemented, and registers are RAZ/WI
+ Errors:
+ -ENODEV: Getting or setting this register is not yet supported
+ -EBUSY: One or more VCPUs are running
+
+ KVM_DEV_ARM_VGIC_GRP_REDIST_REGS
+ Attributes:
+ The attr field of kvm_device_attr encodes two values:
+ bits: | 63 | 62 .. 52 | 51 .. 32 | 31 .... 0 |
+ values: | size | reserved | cpu id | offset |
+
+ All redistributor regs are (rw, 32-bit)
+ For GICv3 some regs are also (rw, 64-bit) according to the specification.
+ In order to perform full 64-bit access 'size' bit should be set to 1.
+ KVM_DEV_ARM_VGIC_64BIT flag value is provided for this purpose.
+
+ The offset is relative to the "Redistributor base address" as defined in
+ the GICv3 specs. Getting or setting such a register has the same effect as
+ reading or writing the register on the actual hardware from the cpu
+ specified with cpu id field. Note that most distributor fields are not
+ banked, but return the same value regardless of the cpu id used to access
+ the register.
+
Limitations:
- Priorities are not implemented, and registers are RAZ/WI
- - Currently only implemented for KVM_DEV_TYPE_ARM_VGIC_V2.
Errors:
-ENODEV: Getting or setting this register is not yet supported
-EBUSY: One or more VCPUs are running
@@ -64,7 +91,7 @@ Groups:
KVM_DEV_ARM_VGIC_GRP_CPU_REGS
Attributes:
The attr field of kvm_device_attr encodes two values:
- bits: | 63 .... 40 | 39 .. 32 | 31 .... 0 |
+ bits: | 63 .... 52 | 51 .. 32 | 31 .... 0 |
values: | reserved | cpu id | offset |
All CPU interface regs are (rw, 32-bit)
diff --git a/arch/arm64/include/uapi/asm/kvm.h b/arch/arm64/include/uapi/asm/kvm.h
index 0cd7b59..249954f 100644
--- a/arch/arm64/include/uapi/asm/kvm.h
+++ b/arch/arm64/include/uapi/asm/kvm.h
@@ -196,13 +196,15 @@ struct kvm_arch_memory_slot {
#define KVM_DEV_ARM_VGIC_GRP_ADDR 0
#define KVM_DEV_ARM_VGIC_GRP_DIST_REGS 1
#define KVM_DEV_ARM_VGIC_GRP_CPU_REGS 2
+#define KVM_DEV_ARM_VGIC_64BIT (1ULL << 63)
#define KVM_DEV_ARM_VGIC_CPUID_SHIFT 32
-#define KVM_DEV_ARM_VGIC_CPUID_MASK (0xffULL << KVM_DEV_ARM_VGIC_CPUID_SHIFT)
+#define KVM_DEV_ARM_VGIC_CPUID_MASK (0xfffffULL << KVM_DEV_ARM_VGIC_CPUID_SHIFT)
#define KVM_DEV_ARM_VGIC_OFFSET_SHIFT 0
#define KVM_DEV_ARM_VGIC_OFFSET_MASK (0xffffffffULL << KVM_DEV_ARM_VGIC_OFFSET_SHIFT)
#define KVM_DEV_ARM_VGIC_GRP_NR_IRQS 3
#define KVM_DEV_ARM_VGIC_GRP_CTRL 4
#define KVM_DEV_ARM_VGIC_CTRL_INIT 0
+#define KVM_DEV_ARM_VGIC_GRP_REDIST_REGS 5
/* KVM_IRQ_LINE irq field index values */
#define KVM_ARM_IRQ_TYPE_SHIFT 24
diff --git a/virt/kvm/arm/vgic-v3-emul.c b/virt/kvm/arm/vgic-v3-emul.c
index e661e7f..8bda714 100644
--- a/virt/kvm/arm/vgic-v3-emul.c
+++ b/virt/kvm/arm/vgic-v3-emul.c
@@ -39,6 +39,7 @@
#include <linux/kvm.h>
#include <linux/kvm_host.h>
#include <linux/interrupt.h>
+#include <linux/uaccess.h>
#include <linux/irqchip/arm-gic-v3.h>
#include <kvm/arm_vgic.h>
@@ -990,6 +991,77 @@ void vgic_v3_dispatch_sgi(struct kvm_vcpu *vcpu, u64 reg)
vgic_kick_vcpus(vcpu->kvm);
}
+static int vgic_v3_attr_regs_access(struct kvm_device *dev,
+ struct kvm_device_attr *attr,
+ bool is_write)
+{
+ const struct vgic_io_range *ranges;
+ phys_addr_t offset;
+ int cpuid, ret;
+ struct vgic_dist *vgic = &dev->kvm->arch.vgic;
+ struct kvm_exit_mmio mmio;
+
+ cpuid = (attr->attr & KVM_DEV_ARM_VGIC_CPUID_MASK) >>
+ KVM_DEV_ARM_VGIC_CPUID_SHIFT;
+
+ switch (attr->group) {
+ case KVM_DEV_ARM_VGIC_GRP_DIST_REGS:
+ offset = attr->attr & KVM_DEV_ARM_VGIC_OFFSET_MASK;
+ mmio.phys_addr = vgic->vgic_dist_base;
+ ranges = vgic_v3_dist_ranges;
+ break;
+ case KVM_DEV_ARM_VGIC_GRP_REDIST_REGS:
+ offset = attr->attr & KVM_DEV_ARM_VGIC_OFFSET_MASK;
+ mmio.phys_addr = vgic->vgic_redist_base;
+ ranges = vgic_redist_ranges;
+ break;
+ default:
+ return -ENXIO;
+ }
+
+ mmio.is_write = is_write;
+
+ if (attr->attr & KVM_DEV_ARM_VGIC_64BIT) {
+ u64 __user *uaddr = (u64 __user *)(long)attr->addr;
+ __le64 data;
+
+ if (is_write) {
+ u64 reg;
+
+ if (get_user(reg, uaddr))
+ return -EFAULT;
+ data = cpu_to_le64(reg);
+ }
+
+ mmio.data = &data;
+ ret = vgic_attr_regs_access(dev, ranges, &mmio, offset,
+ sizeof(data), cpuid);
+
+ if (!ret && !is_write)
+ ret = put_user(le64_to_cpu(data), uaddr);
+ } else {
+ u32 __user *uaddr = (u32 __user *)(long)attr->addr;
+ __le32 data;
+
+ if (is_write) {
+ u32 reg;
+
+ if (get_user(reg, uaddr))
+ return -EFAULT;
+ data = cpu_to_le32(reg);
+ }
+
+ mmio.data = &data;
+ ret = vgic_attr_regs_access(dev, ranges, &mmio, offset,
+ sizeof(data), cpuid);
+
+ if (!ret && !is_write)
+ ret = put_user(le32_to_cpu(data), uaddr);
+ }
+
+ return ret;
+}
+
static int vgic_v3_create(struct kvm_device *dev, u32 type)
{
return kvm_vgic_create(dev->kvm, type);
@@ -1009,13 +1081,7 @@ static int vgic_v3_set_attr(struct kvm_device *dev,
if (ret != -ENXIO)
return ret;
- switch (attr->group) {
- case KVM_DEV_ARM_VGIC_GRP_DIST_REGS:
- case KVM_DEV_ARM_VGIC_GRP_CPU_REGS:
- return -ENXIO;
- }
-
- return -ENXIO;
+ return vgic_v3_attr_regs_access(dev, attr, true);
}
static int vgic_v3_get_attr(struct kvm_device *dev,
@@ -1027,18 +1093,14 @@ static int vgic_v3_get_attr(struct kvm_device *dev,
if (ret != -ENXIO)
return ret;
- switch (attr->group) {
- case KVM_DEV_ARM_VGIC_GRP_DIST_REGS:
- case KVM_DEV_ARM_VGIC_GRP_CPU_REGS:
- return -ENXIO;
- }
-
- return -ENXIO;
+ return vgic_v3_attr_regs_access(dev, attr, false);
}
static int vgic_v3_has_attr(struct kvm_device *dev,
struct kvm_device_attr *attr)
{
+ phys_addr_t offset;
+
switch (attr->group) {
case KVM_DEV_ARM_VGIC_GRP_ADDR:
switch (attr->attr) {
@@ -1051,6 +1113,11 @@ static int vgic_v3_has_attr(struct kvm_device *dev,
}
break;
case KVM_DEV_ARM_VGIC_GRP_DIST_REGS:
+ offset = attr->attr & KVM_DEV_ARM_VGIC_OFFSET_MASK;
+ return vgic_has_attr_regs(vgic_v3_dist_ranges, offset);
+ case KVM_DEV_ARM_VGIC_GRP_REDIST_REGS:
+ offset = attr->attr & KVM_DEV_ARM_VGIC_OFFSET_MASK;
+ return vgic_has_attr_regs(vgic_redist_ranges, offset);
case KVM_DEV_ARM_VGIC_GRP_CPU_REGS:
return -ENXIO;
case KVM_DEV_ARM_VGIC_GRP_NR_IRQS:
diff --git a/virt/kvm/arm/vgic.c b/virt/kvm/arm/vgic.c
index 33b00e5..9aa802b 100644
--- a/virt/kvm/arm/vgic.c
+++ b/virt/kvm/arm/vgic.c
@@ -2468,6 +2468,7 @@ int vgic_attr_regs_access(struct kvm_device *dev,
* access. For 64-bit registers we have to split up the operation.
*/
mmio->len = sizeof(u32);
+ mmio->private = vcpu; /* For redistributor handlers */
mmio->phys_addr += offset;
offset -= r->base;
r->handle_mmio(vcpu, mmio, offset);
--
2.4.4
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