[PATCH 03/25] KVM: arm/arm64: vgic: Implement support for userspace access
Marc Zyngier
marc.zyngier at arm.com
Thu Feb 9 06:59:01 PST 2017
From: Vijaya Kumar K <Vijaya.Kumar at cavium.com>
Read and write of some registers like ISPENDR and ICPENDR
from userspace requires special handling when compared to
guest access for these registers.
Refer to Documentation/virtual/kvm/devices/arm-vgic-v3.txt
for handling of ISPENDR, ICPENDR registers handling.
Add infrastructure to support guest and userspace read
and write for the required registers
Also moved vgic_uaccess from vgic-mmio-v2.c to vgic-mmio.c
Signed-off-by: Vijaya Kumar K <Vijaya.Kumar at cavium.com>
Reviewed-by: Christoffer Dall <christoffer.dall at linaro.org>
Reviewed-by: Eric Auger <eric.auger at redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier at arm.com>
---
virt/kvm/arm/vgic/vgic-mmio-v2.c | 25 -----------
virt/kvm/arm/vgic/vgic-mmio-v3.c | 96 ++++++++++++++++++++++++++++++++--------
virt/kvm/arm/vgic/vgic-mmio.c | 78 +++++++++++++++++++++++++++++---
virt/kvm/arm/vgic/vgic-mmio.h | 19 ++++++++
4 files changed, 169 insertions(+), 49 deletions(-)
diff --git a/virt/kvm/arm/vgic/vgic-mmio-v2.c b/virt/kvm/arm/vgic/vgic-mmio-v2.c
index 07e67f1..270eb4a 100644
--- a/virt/kvm/arm/vgic/vgic-mmio-v2.c
+++ b/virt/kvm/arm/vgic/vgic-mmio-v2.c
@@ -407,31 +407,6 @@ 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_cpuif_uaccess(struct kvm_vcpu *vcpu, bool is_write,
int offset, u32 *val)
{
diff --git a/virt/kvm/arm/vgic/vgic-mmio-v3.c b/virt/kvm/arm/vgic/vgic-mmio-v3.c
index 2aca52a..3548bb2 100644
--- a/virt/kvm/arm/vgic/vgic-mmio-v3.c
+++ b/virt/kvm/arm/vgic/vgic-mmio-v3.c
@@ -207,6 +207,60 @@ static unsigned long vgic_mmio_read_v3_idregs(struct kvm_vcpu *vcpu,
return 0;
}
+static unsigned long vgic_v3_uaccess_read_pending(struct kvm_vcpu *vcpu,
+ gpa_t addr, unsigned int len)
+{
+ u32 intid = VGIC_ADDR_TO_INTID(addr, 1);
+ u32 value = 0;
+ int i;
+
+ /*
+ * pending state of interrupt is latched in pending_latch variable.
+ * Userspace will save and restore pending state and line_level
+ * separately.
+ * Refer to Documentation/virtual/kvm/devices/arm-vgic-v3.txt
+ * for handling of ISPENDR and ICPENDR.
+ */
+ for (i = 0; i < len * 8; i++) {
+ struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, intid + i);
+
+ if (irq->pending_latch)
+ value |= (1U << i);
+
+ vgic_put_irq(vcpu->kvm, irq);
+ }
+
+ return value;
+}
+
+static void vgic_v3_uaccess_write_pending(struct kvm_vcpu *vcpu,
+ gpa_t addr, unsigned int len,
+ unsigned long val)
+{
+ u32 intid = VGIC_ADDR_TO_INTID(addr, 1);
+ int i;
+
+ for (i = 0; i < len * 8; i++) {
+ struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, intid + i);
+
+ spin_lock(&irq->irq_lock);
+ if (test_bit(i, &val)) {
+ /*
+ * pending_latch is set irrespective of irq type
+ * (level or edge) to avoid dependency that VM should
+ * restore irq config before pending info.
+ */
+ irq->pending_latch = true;
+ vgic_queue_irq_unlock(vcpu->kvm, irq);
+ } else {
+ irq->pending_latch = false;
+ spin_unlock(&irq->irq_lock);
+ }
+
+ vgic_put_irq(vcpu->kvm, irq);
+ }
+}
+
/* We want to avoid outer shareable. */
u64 vgic_sanitise_shareability(u64 field)
{
@@ -356,7 +410,7 @@ static void vgic_mmio_write_pendbase(struct kvm_vcpu *vcpu,
* We take some special care here to fix the calculation of the register
* offset.
*/
-#define REGISTER_DESC_WITH_BITS_PER_IRQ_SHARED(off, rd, wr, bpi, acc) \
+#define REGISTER_DESC_WITH_BITS_PER_IRQ_SHARED(off, rd, wr, ur, uw, bpi, acc) \
{ \
.reg_offset = off, \
.bits_per_irq = bpi, \
@@ -371,6 +425,8 @@ static void vgic_mmio_write_pendbase(struct kvm_vcpu *vcpu,
.access_flags = acc, \
.read = rd, \
.write = wr, \
+ .uaccess_read = ur, \
+ .uaccess_write = uw, \
}
static const struct vgic_register_region vgic_v3_dist_registers[] = {
@@ -378,40 +434,42 @@ static const struct vgic_register_region vgic_v3_dist_registers[] = {
vgic_mmio_read_v3_misc, vgic_mmio_write_v3_misc, 16,
VGIC_ACCESS_32bit),
REGISTER_DESC_WITH_BITS_PER_IRQ_SHARED(GICD_IGROUPR,
- vgic_mmio_read_rao, vgic_mmio_write_wi, 1,
+ vgic_mmio_read_rao, vgic_mmio_write_wi, NULL, NULL, 1,
VGIC_ACCESS_32bit),
REGISTER_DESC_WITH_BITS_PER_IRQ_SHARED(GICD_ISENABLER,
- vgic_mmio_read_enable, vgic_mmio_write_senable, 1,
+ vgic_mmio_read_enable, vgic_mmio_write_senable, NULL, NULL, 1,
VGIC_ACCESS_32bit),
REGISTER_DESC_WITH_BITS_PER_IRQ_SHARED(GICD_ICENABLER,
- vgic_mmio_read_enable, vgic_mmio_write_cenable, 1,
+ vgic_mmio_read_enable, vgic_mmio_write_cenable, NULL, NULL, 1,
VGIC_ACCESS_32bit),
REGISTER_DESC_WITH_BITS_PER_IRQ_SHARED(GICD_ISPENDR,
- vgic_mmio_read_pending, vgic_mmio_write_spending, 1,
+ vgic_mmio_read_pending, vgic_mmio_write_spending,
+ vgic_v3_uaccess_read_pending, vgic_v3_uaccess_write_pending, 1,
VGIC_ACCESS_32bit),
REGISTER_DESC_WITH_BITS_PER_IRQ_SHARED(GICD_ICPENDR,
- vgic_mmio_read_pending, vgic_mmio_write_cpending, 1,
+ vgic_mmio_read_pending, vgic_mmio_write_cpending,
+ vgic_mmio_read_raz, vgic_mmio_write_wi, 1,
VGIC_ACCESS_32bit),
REGISTER_DESC_WITH_BITS_PER_IRQ_SHARED(GICD_ISACTIVER,
- vgic_mmio_read_active, vgic_mmio_write_sactive, 1,
+ vgic_mmio_read_active, vgic_mmio_write_sactive, NULL, NULL, 1,
VGIC_ACCESS_32bit),
REGISTER_DESC_WITH_BITS_PER_IRQ_SHARED(GICD_ICACTIVER,
- vgic_mmio_read_active, vgic_mmio_write_cactive, 1,
+ vgic_mmio_read_active, vgic_mmio_write_cactive, NULL, NULL, 1,
VGIC_ACCESS_32bit),
REGISTER_DESC_WITH_BITS_PER_IRQ_SHARED(GICD_IPRIORITYR,
- vgic_mmio_read_priority, vgic_mmio_write_priority, 8,
- VGIC_ACCESS_32bit | VGIC_ACCESS_8bit),
+ vgic_mmio_read_priority, vgic_mmio_write_priority, NULL, NULL,
+ 8, VGIC_ACCESS_32bit | VGIC_ACCESS_8bit),
REGISTER_DESC_WITH_BITS_PER_IRQ_SHARED(GICD_ITARGETSR,
- vgic_mmio_read_raz, vgic_mmio_write_wi, 8,
+ vgic_mmio_read_raz, vgic_mmio_write_wi, NULL, NULL, 8,
VGIC_ACCESS_32bit | VGIC_ACCESS_8bit),
REGISTER_DESC_WITH_BITS_PER_IRQ_SHARED(GICD_ICFGR,
- vgic_mmio_read_config, vgic_mmio_write_config, 2,
+ vgic_mmio_read_config, vgic_mmio_write_config, NULL, NULL, 2,
VGIC_ACCESS_32bit),
REGISTER_DESC_WITH_BITS_PER_IRQ_SHARED(GICD_IGRPMODR,
- vgic_mmio_read_raz, vgic_mmio_write_wi, 1,
+ vgic_mmio_read_raz, vgic_mmio_write_wi, NULL, NULL, 1,
VGIC_ACCESS_32bit),
REGISTER_DESC_WITH_BITS_PER_IRQ_SHARED(GICD_IROUTER,
- vgic_mmio_read_irouter, vgic_mmio_write_irouter, 64,
+ vgic_mmio_read_irouter, vgic_mmio_write_irouter, NULL, NULL, 64,
VGIC_ACCESS_64bit | VGIC_ACCESS_32bit),
REGISTER_DESC_WITH_LENGTH(GICD_IDREGS,
vgic_mmio_read_v3_idregs, vgic_mmio_write_wi, 48,
@@ -449,11 +507,13 @@ static const struct vgic_register_region vgic_v3_sgibase_registers[] = {
REGISTER_DESC_WITH_LENGTH(GICR_ICENABLER0,
vgic_mmio_read_enable, vgic_mmio_write_cenable, 4,
VGIC_ACCESS_32bit),
- REGISTER_DESC_WITH_LENGTH(GICR_ISPENDR0,
- vgic_mmio_read_pending, vgic_mmio_write_spending, 4,
+ REGISTER_DESC_WITH_LENGTH_UACCESS(GICR_ISPENDR0,
+ vgic_mmio_read_pending, vgic_mmio_write_spending,
+ vgic_v3_uaccess_read_pending, vgic_v3_uaccess_write_pending, 4,
VGIC_ACCESS_32bit),
- REGISTER_DESC_WITH_LENGTH(GICR_ICPENDR0,
- vgic_mmio_read_pending, vgic_mmio_write_cpending, 4,
+ REGISTER_DESC_WITH_LENGTH_UACCESS(GICR_ICPENDR0,
+ vgic_mmio_read_pending, vgic_mmio_write_cpending,
+ vgic_mmio_read_raz, vgic_mmio_write_wi, 4,
VGIC_ACCESS_32bit),
REGISTER_DESC_WITH_LENGTH(GICR_ISACTIVER0,
vgic_mmio_read_active, vgic_mmio_write_sactive, 4,
diff --git a/virt/kvm/arm/vgic/vgic-mmio.c b/virt/kvm/arm/vgic/vgic-mmio.c
index 2670d39..3fab264 100644
--- a/virt/kvm/arm/vgic/vgic-mmio.c
+++ b/virt/kvm/arm/vgic/vgic-mmio.c
@@ -475,6 +475,74 @@ static bool check_region(const struct kvm *kvm,
return false;
}
+static const struct vgic_register_region *
+vgic_get_mmio_region(struct kvm_vcpu *vcpu, struct vgic_io_device *iodev,
+ gpa_t addr, int len)
+{
+ const struct vgic_register_region *region;
+
+ region = vgic_find_mmio_region(iodev->regions, iodev->nr_regions,
+ addr - iodev->base_addr);
+ if (!region || !check_region(vcpu->kvm, region, addr, len))
+ return NULL;
+
+ return region;
+}
+
+static int vgic_uaccess_read(struct kvm_vcpu *vcpu, struct kvm_io_device *dev,
+ gpa_t addr, u32 *val)
+{
+ struct vgic_io_device *iodev = kvm_to_vgic_iodev(dev);
+ const struct vgic_register_region *region;
+ struct kvm_vcpu *r_vcpu;
+
+ region = vgic_get_mmio_region(vcpu, iodev, addr, sizeof(u32));
+ if (!region) {
+ *val = 0;
+ return 0;
+ }
+
+ r_vcpu = iodev->redist_vcpu ? iodev->redist_vcpu : vcpu;
+ if (region->uaccess_read)
+ *val = region->uaccess_read(r_vcpu, addr, sizeof(u32));
+ else
+ *val = region->read(r_vcpu, addr, sizeof(u32));
+
+ return 0;
+}
+
+static int vgic_uaccess_write(struct kvm_vcpu *vcpu, struct kvm_io_device *dev,
+ gpa_t addr, const u32 *val)
+{
+ struct vgic_io_device *iodev = kvm_to_vgic_iodev(dev);
+ const struct vgic_register_region *region;
+ struct kvm_vcpu *r_vcpu;
+
+ region = vgic_get_mmio_region(vcpu, iodev, addr, sizeof(u32));
+ if (!region)
+ return 0;
+
+ r_vcpu = iodev->redist_vcpu ? iodev->redist_vcpu : vcpu;
+ if (region->uaccess_write)
+ region->uaccess_write(r_vcpu, addr, sizeof(u32), *val);
+ else
+ region->write(r_vcpu, addr, sizeof(u32), *val);
+
+ return 0;
+}
+
+/*
+ * Userland access to VGIC registers.
+ */
+int vgic_uaccess(struct kvm_vcpu *vcpu, struct vgic_io_device *dev,
+ bool is_write, int offset, u32 *val)
+{
+ if (is_write)
+ return vgic_uaccess_write(vcpu, &dev->dev, offset, val);
+ else
+ return vgic_uaccess_read(vcpu, &dev->dev, offset, val);
+}
+
static int dispatch_mmio_read(struct kvm_vcpu *vcpu, struct kvm_io_device *dev,
gpa_t addr, int len, void *val)
{
@@ -482,9 +550,8 @@ static int dispatch_mmio_read(struct kvm_vcpu *vcpu, struct kvm_io_device *dev,
const struct vgic_register_region *region;
unsigned long data = 0;
- region = vgic_find_mmio_region(iodev->regions, iodev->nr_regions,
- addr - iodev->base_addr);
- if (!region || !check_region(vcpu->kvm, region, addr, len)) {
+ region = vgic_get_mmio_region(vcpu, iodev, addr, len);
+ if (!region) {
memset(val, 0, len);
return 0;
}
@@ -515,9 +582,8 @@ static int dispatch_mmio_write(struct kvm_vcpu *vcpu, struct kvm_io_device *dev,
const struct vgic_register_region *region;
unsigned long data = vgic_data_mmio_bus_to_host(val, len);
- region = vgic_find_mmio_region(iodev->regions, iodev->nr_regions,
- addr - iodev->base_addr);
- if (!region || !check_region(vcpu->kvm, region, addr, len))
+ region = vgic_get_mmio_region(vcpu, iodev, addr, len);
+ if (!region)
return 0;
switch (iodev->iodev_type) {
diff --git a/virt/kvm/arm/vgic/vgic-mmio.h b/virt/kvm/arm/vgic/vgic-mmio.h
index 84961b4..7b30296 100644
--- a/virt/kvm/arm/vgic/vgic-mmio.h
+++ b/virt/kvm/arm/vgic/vgic-mmio.h
@@ -34,6 +34,10 @@ struct vgic_register_region {
gpa_t addr, unsigned int len,
unsigned long val);
};
+ unsigned long (*uaccess_read)(struct kvm_vcpu *vcpu, gpa_t addr,
+ unsigned int len);
+ void (*uaccess_write)(struct kvm_vcpu *vcpu, gpa_t addr,
+ unsigned int len, unsigned long val);
};
extern struct kvm_io_device_ops kvm_io_gic_ops;
@@ -86,6 +90,18 @@ extern struct kvm_io_device_ops kvm_io_gic_ops;
.write = wr, \
}
+#define REGISTER_DESC_WITH_LENGTH_UACCESS(off, rd, wr, urd, uwr, length, acc) \
+ { \
+ .reg_offset = off, \
+ .bits_per_irq = 0, \
+ .len = length, \
+ .access_flags = acc, \
+ .read = rd, \
+ .write = wr, \
+ .uaccess_read = urd, \
+ .uaccess_write = uwr, \
+ }
+
int kvm_vgic_register_mmio_region(struct kvm *kvm, struct kvm_vcpu *vcpu,
struct vgic_register_region *reg_desc,
struct vgic_io_device *region,
@@ -158,6 +174,9 @@ void vgic_mmio_write_config(struct kvm_vcpu *vcpu,
gpa_t addr, unsigned int len,
unsigned long val);
+int vgic_uaccess(struct kvm_vcpu *vcpu, struct vgic_io_device *dev,
+ bool is_write, int offset, u32 *val);
+
unsigned int vgic_v2_init_dist_iodev(struct vgic_io_device *dev);
unsigned int vgic_v3_init_dist_iodev(struct vgic_io_device *dev);
--
2.1.4
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