Rework the VGIC initialization slightly to allow initialization of the vgic cpu-specific state even if the irqchip (the VGIC) hasn't been created by user space yet. This is safe, because the vgic data structures are already allocated when the CPU is allocated if VGIC support is compiled into the kernel. Further, the init process does not depend on any other information and the sacrifice is a slight performance degradation for creating VMs in the no-VGIC case.

The reason is that the new device control API doesn't mandate creating the VGIC before creating the VCPU and it is unreasonable to require user space to create the VGIC before creating the VCPUs.

At the same time move the irqchip_in_kernel check out of kvm_vcpu_first_run_init and into the init function to make the per-vcpu and global init functions symmetric and add comments on the exported functions making it a bit easier to understand the init flow by only looking at vgic.c.

Acked-by: Marc Zyngier marc.zyngier@arm.com Signed-off-by: Christoffer Dall christoffer.dall@linaro.org --- arch/arm/kvm/arm.c | 7 ++++--- virt/kvm/arm/vgic.c | 22 +++++++++++++++++++--- 2 files changed, 23 insertions(+), 6 deletions(-)

diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c index 13205bd..c9fe9d7 100644 --- a/arch/arm/kvm/arm.c +++ b/arch/arm/kvm/arm.c @@ -464,6 +464,8 @@ static void update_vttbr(struct kvm *kvm)

static int kvm_vcpu_first_run_init(struct kvm_vcpu *vcpu) { + int ret; + if (likely(vcpu->arch.has_run_once)) return 0;

@@ -473,9 +475,8 @@ static int kvm_vcpu_first_run_init(struct kvm_vcpu *vcpu) * Initialize the VGIC before running a vcpu the first time on * this VM. */ - if (irqchip_in_kernel(vcpu->kvm) && - unlikely(!vgic_initialized(vcpu->kvm))) { - int ret = kvm_vgic_init(vcpu->kvm); + if (unlikely(!vgic_initialized(vcpu->kvm))) { + ret = kvm_vgic_init(vcpu->kvm); if (ret) return ret; } diff --git a/virt/kvm/arm/vgic.c b/virt/kvm/arm/vgic.c index 81e9481..5e9df47 100644 --- a/virt/kvm/arm/vgic.c +++ b/virt/kvm/arm/vgic.c @@ -1243,15 +1243,19 @@ static irqreturn_t vgic_maintenance_handler(int irq, void *data) return IRQ_HANDLED; }

+/** + * kvm_vgic_vcpu_init - Initialize per-vcpu VGIC state + * @vcpu: pointer to the vcpu struct + * + * Initialize the vgic_cpu struct and vgic_dist struct fields pertaining to + * this vcpu and enable the VGIC for this VCPU + */ int kvm_vgic_vcpu_init(struct kvm_vcpu *vcpu) { struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu; struct vgic_dist *dist = &vcpu->kvm->arch.vgic; int i;

- if (!irqchip_in_kernel(vcpu->kvm)) - return 0; - if (vcpu->vcpu_id >= VGIC_MAX_CPUS) return -EBUSY;

@@ -1383,10 +1387,22 @@ out: return ret; }

+/** + * kvm_vgic_init - Initialize global VGIC state before running any VCPUs + * @kvm: pointer to the kvm struct + * + * Map the virtual CPU interface into the VM before running any VCPUs. We + * can't do this at creation time, because user space must first set the + * virtual CPU interface address in the guest physical address space. Also + * initialize the ITARGETSRn regs to 0 on the emulated distributor. + */ int kvm_vgic_init(struct kvm *kvm) { int ret = 0, i;

+ if (!irqchip_in_kernel(kvm)) + return 0; + mutex_lock(&kvm->lock);

if (vgic_initialized(kvm))

Support setting the distributor and cpu interface base addresses in the VM physical address space through the KVM_{SET,GET}_DEVICE_ATTR API in addition to the ARM specific API.

This has the added benefit of being able to share more code in user space and do things in a uniform manner.

Also deprecate the older API at the same time, but backwards compatibility will be maintained.

Signed-off-by: Christoffer Dall christoffer.dall@linaro.org --- Changelog[v4]: - Move VGIC device control API defines to later patch where they are used - Remove unused variable declaration

Changelog[v3]: - Spelling nits - Fix error codes from vgic_get_attr

Changelog[v2]: - None

Documentation/virtual/kvm/api.txt | 7 ++- Documentation/virtual/kvm/devices/arm-vgic.txt | 11 ++++ arch/arm/include/uapi/asm/kvm.h | 2 + arch/arm/kvm/arm.c | 2 +- include/kvm/arm_vgic.h | 2 +- virt/kvm/arm/vgic.c | 87 ++++++++++++++++++++++---- 6 files changed, 96 insertions(+), 15 deletions(-)

diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt index a30035d..867112f 100644 --- a/Documentation/virtual/kvm/api.txt +++ b/Documentation/virtual/kvm/api.txt @@ -2391,7 +2391,8 @@ struct kvm_reg_list { This ioctl returns the guest registers that are supported for the KVM_GET_ONE_REG/KVM_SET_ONE_REG calls.

-4.85 KVM_ARM_SET_DEVICE_ADDR + +4.85 KVM_ARM_SET_DEVICE_ADDR (deprecated)

Capability: KVM_CAP_ARM_SET_DEVICE_ADDR Architectures: arm, arm64 @@ -2429,6 +2430,10 @@ must be called after calling KVM_CREATE_IRQCHIP, but before calling KVM_RUN on any of the VCPUs. Calling this ioctl twice for any of the base addresses will return -EEXIST.

+Note, this IOCTL is deprecated and the more flexible SET/GET_DEVICE_ATTR API +should be used instead. + + 4.86 KVM_PPC_RTAS_DEFINE_TOKEN

Capability: KVM_CAP_PPC_RTAS diff --git a/Documentation/virtual/kvm/devices/arm-vgic.txt b/Documentation/virtual/kvm/devices/arm-vgic.txt index 38f27f7..c9febb2 100644 --- a/Documentation/virtual/kvm/devices/arm-vgic.txt +++ b/Documentation/virtual/kvm/devices/arm-vgic.txt @@ -8,3 +8,14 @@ Only one VGIC instance may be instantiated through either this API or the legacy KVM_CREATE_IRQCHIP api. The created VGIC will act as the VM interrupt controller, requiring emulated user-space devices to inject interrupts to the VGIC instead of directly to CPUs. + +Groups: + KVM_DEV_ARM_VGIC_GRP_ADDR + Attributes: + KVM_VGIC_V2_ADDR_TYPE_DIST (rw, 64-bit) + Base address in the guest physical address space of the GIC distributor + register mappings. + + KVM_VGIC_V2_ADDR_TYPE_CPU (rw, 64-bit) + Base address in the guest physical address space of the GIC virtual cpu + interface register mappings. diff --git a/arch/arm/include/uapi/asm/kvm.h b/arch/arm/include/uapi/asm/kvm.h index 835b867..76a7427 100644 --- a/arch/arm/include/uapi/asm/kvm.h +++ b/arch/arm/include/uapi/asm/kvm.h @@ -163,6 +163,8 @@ struct kvm_arch_memory_slot { #define KVM_REG_ARM_VFP_FPINST 0x1009 #define KVM_REG_ARM_VFP_FPINST2 0x100A

+/* Device Control API: ARM VGIC */ +#define KVM_DEV_ARM_VGIC_GRP_ADDR 0

/* KVM_IRQ_LINE irq field index values */ #define KVM_ARM_IRQ_TYPE_SHIFT 24 diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c index cc7c41a..f290b22 100644 --- a/arch/arm/kvm/arm.c +++ b/arch/arm/kvm/arm.c @@ -776,7 +776,7 @@ static int kvm_vm_ioctl_set_device_addr(struct kvm *kvm, case KVM_ARM_DEVICE_VGIC_V2: if (!vgic_present) return -ENXIO; - return kvm_vgic_set_addr(kvm, type, dev_addr->addr); + return kvm_vgic_addr(kvm, type, &dev_addr->addr, true); default: return -ENODEV; } diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h index 7e2d158..be85127 100644 --- a/include/kvm/arm_vgic.h +++ b/include/kvm/arm_vgic.h @@ -144,7 +144,7 @@ struct kvm_run; struct kvm_exit_mmio;

#ifdef CONFIG_KVM_ARM_VGIC -int kvm_vgic_set_addr(struct kvm *kvm, unsigned long type, u64 addr); +int kvm_vgic_addr(struct kvm *kvm, unsigned long type, u64 *addr, bool write); int kvm_vgic_hyp_init(void); int kvm_vgic_init(struct kvm *kvm); int kvm_vgic_create(struct kvm *kvm); diff --git a/virt/kvm/arm/vgic.c b/virt/kvm/arm/vgic.c index b15d6c1..45db48d 100644 --- a/virt/kvm/arm/vgic.c +++ b/virt/kvm/arm/vgic.c @@ -1495,6 +1495,12 @@ static int vgic_ioaddr_assign(struct kvm *kvm, phys_addr_t *ioaddr, { int ret;

+ if (addr & ~KVM_PHYS_MASK) + return -E2BIG; + + if (addr & (SZ_4K - 1)) + return -EINVAL; + if (!IS_VGIC_ADDR_UNDEF(*ioaddr)) return -EEXIST; if (addr + size < addr) @@ -1507,26 +1513,41 @@ static int vgic_ioaddr_assign(struct kvm *kvm, phys_addr_t *ioaddr, return ret; }

-int kvm_vgic_set_addr(struct kvm *kvm, unsigned long type, u64 addr) +/** + * kvm_vgic_addr - set or get vgic VM base addresses + * @kvm: pointer to the vm struct + * @type: the VGIC addr type, one of KVM_VGIC_V2_ADDR_TYPE_XXX + * @addr: pointer to address value + * @write: if true set the address in the VM address space, if false read the + * address + * + * Set or get the vgic base addresses for the distributor and the virtual CPU + * interface in the VM physical address space. These addresses are properties + * of the emulated core/SoC and therefore user space initially knows this + * information. + */ +int kvm_vgic_addr(struct kvm *kvm, unsigned long type, u64 *addr, bool write) { int r = 0; struct vgic_dist *vgic = &kvm->arch.vgic;

- if (addr & ~KVM_PHYS_MASK) - return -E2BIG; - - if (addr & (SZ_4K - 1)) - return -EINVAL; - mutex_lock(&kvm->lock); switch (type) { case KVM_VGIC_V2_ADDR_TYPE_DIST: - r = vgic_ioaddr_assign(kvm, &vgic->vgic_dist_base, - addr, KVM_VGIC_V2_DIST_SIZE); + if (write) { + r = vgic_ioaddr_assign(kvm, &vgic->vgic_dist_base, + *addr, KVM_VGIC_V2_DIST_SIZE); + } else { + *addr = vgic->vgic_dist_base; + } break; case KVM_VGIC_V2_ADDR_TYPE_CPU: - r = vgic_ioaddr_assign(kvm, &vgic->vgic_cpu_base, - addr, KVM_VGIC_V2_CPU_SIZE); + if (write) { + r = vgic_ioaddr_assign(kvm, &vgic->vgic_cpu_base, + *addr, KVM_VGIC_V2_CPU_SIZE); + } else { + *addr = vgic->vgic_cpu_base; + } break; default: r = -ENODEV; @@ -1538,16 +1559,58 @@ int kvm_vgic_set_addr(struct kvm *kvm, unsigned long type, u64 addr)

static int vgic_set_attr(struct kvm_device *dev, struct kvm_device_attr *attr) { + int r; + + switch (attr->group) { + case KVM_DEV_ARM_VGIC_GRP_ADDR: { + u64 __user *uaddr = (u64 __user *)(long)attr->addr; + u64 addr; + unsigned long type = (unsigned long)attr->attr; + + if (copy_from_user(&addr, uaddr, sizeof(addr))) + return -EFAULT; + + r = kvm_vgic_addr(dev->kvm, type, &addr, true); + return (r == -ENODEV) ? -ENXIO : r; + } + } + return -ENXIO; }

static int vgic_get_attr(struct kvm_device *dev, struct kvm_device_attr *attr) { - return -ENXIO; + int r = -ENXIO; + + switch (attr->group) { + case KVM_DEV_ARM_VGIC_GRP_ADDR: { + u64 __user *uaddr = (u64 __user *)(long)attr->addr; + u64 addr; + unsigned long type = (unsigned long)attr->attr; + + r = kvm_vgic_addr(dev->kvm, type, &addr, false); + if (r) + return (r == -ENODEV) ? -ENXIO : r; + + if (copy_to_user(uaddr, &addr, sizeof(addr))) + return -EFAULT; + } + } + + return r; }

static int vgic_has_attr(struct kvm_device *dev, struct kvm_device_attr *attr) { + switch (attr->group) { + case KVM_DEV_ARM_VGIC_GRP_ADDR: + switch (attr->attr) { + case KVM_VGIC_V2_ADDR_TYPE_DIST: + case KVM_VGIC_V2_ADDR_TYPE_CPU: + return 0; + } + break; + } return -ENXIO; }

Define CPU interface offsets for the GICC_ABPR, GICC_APR, and GICC_IIDR registers. Define distributor registers for the GICD_SPENDSGIR and the GICD_CPENDSGIR. KVM/ARM needs to know about these definitions to fully support save/restore of the VGIC.

Also define some masks and shifts for the various GICH_VMCR fields.

Cc: Thomas Gleixner tglx@linutronix.de Acked-by: Marc Zyngier marc.zyngier@arm.com Signed-off-by: Christoffer Dall christoffer.dall@linaro.org --- include/linux/irqchip/arm-gic.h | 12 ++++++++++++ 1 file changed, 12 insertions(+)

diff --git a/include/linux/irqchip/arm-gic.h b/include/linux/irqchip/arm-gic.h index cac496b..0ceb389 100644 --- a/include/linux/irqchip/arm-gic.h +++ b/include/linux/irqchip/arm-gic.h @@ -17,6 +17,9 @@ #define GIC_CPU_EOI 0x10 #define GIC_CPU_RUNNINGPRI 0x14 #define GIC_CPU_HIGHPRI 0x18 +#define GIC_CPU_ALIAS_BINPOINT 0x1c +#define GIC_CPU_ACTIVEPRIO 0xd0 +#define GIC_CPU_IDENT 0xfc

#define GIC_DIST_CTRL 0x000 #define GIC_DIST_CTR 0x004 @@ -56,6 +59,15 @@ #define GICH_LR_ACTIVE_BIT (1 << 29) #define GICH_LR_EOI (1 << 19)

+#define GICH_VMCR_CTRL_SHIFT 0 +#define GICH_VMCR_CTRL_MASK (0x21f << GICH_VMCR_CTRL_SHIFT) +#define GICH_VMCR_PRIMASK_SHIFT 27 +#define GICH_VMCR_PRIMASK_MASK (0x1f << GICH_VMCR_PRIMASK_SHIFT) +#define GICH_VMCR_BINPOINT_SHIFT 21 +#define GICH_VMCR_BINPOINT_MASK (0x7 << GICH_VMCR_BINPOINT_SHIFT) +#define GICH_VMCR_ALIAS_BINPOINT_SHIFT 18 +#define GICH_VMCR_ALIAS_BINPOINT_MASK (0x7 << GICH_VMCR_ALIAS_BINPOINT_SHIFT) + #define GICH_MISR_EOI (1 << 0) #define GICH_MISR_U (1 << 1)

The arch-generic KVM code expects the cpu field of a vcpu to be -1 if the vcpu is no longer assigned to a cpu. This is used for the optimized make_all_cpus_request path and will be used by the vgic code to check that no vcpus are running.

Signed-off-by: Christoffer Dall christoffer.dall@linaro.org --- Changelog[v4]: - New in series

arch/arm/kvm/arm.c | 7 +++++++ 1 file changed, 7 insertions(+)

diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c index f290b22..b92ff6d3 100644 --- a/arch/arm/kvm/arm.c +++ b/arch/arm/kvm/arm.c @@ -342,6 +342,13 @@ void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)

void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu) { + /* + * The arch-generic KVM code expects the cpu field of a vcpu to be -1 + * if the vcpu is no longer assigned to a cpu. This is used for the + * optimized make_all_cpus_request path. + */ + vcpu->cpu = -1; + kvm_arm_set_running_vcpu(NULL); }

Add infrastructure to handle distributor and cpu interface register accesses through the KVM_{GET/SET}_DEVICE_ATTR interface by adding the KVM_DEV_ARM_VGIC_GRP_DIST_REGS and KVM_DEV_ARM_VGIC_GRP_CPU_REGS groups and defining the semantics of the attr field to be the MMIO offset as specified in the GICv2 specs.

Missing register accesses or other changes in individual register access functions to support save/restore of the VGIC state is added in subsequent patches.

Signed-off-by: Christoffer Dall christoffer.dall@linaro.org --- Changelog[v4]: - Factored out setting vcpu->cpu = -1 on vcpu_put to separate patch. - Added comment to vgic_attr_regs_access and changed exit handling path.

Changelog[v3]: - Spelling and formatting nits - Fill in the phys_addr in kvm_exit_mmio - Put kvm_exit_mmio matching struct on stack - Change if-else-if to switch statement in vgic_attr_regs_access - Properly synchronize access to the VGIC with all VCPUs and the VM structure, ensuring no VCPUs are running while user space is accessing VGIC registers.

Changelog[v2]: - Added implementation specific format for the GICC_APRn registers.

Documentation/virtual/kvm/devices/arm-vgic.txt | 52 ++++++++ arch/arm/include/uapi/asm/kvm.h | 6 + virt/kvm/arm/vgic.c | 178 +++++++++++++++++++++++++ 3 files changed, 236 insertions(+)

diff --git a/Documentation/virtual/kvm/devices/arm-vgic.txt b/Documentation/virtual/kvm/devices/arm-vgic.txt index c9febb2..7f4e91b 100644 --- a/Documentation/virtual/kvm/devices/arm-vgic.txt +++ b/Documentation/virtual/kvm/devices/arm-vgic.txt @@ -19,3 +19,55 @@ Groups: KVM_VGIC_V2_ADDR_TYPE_CPU (rw, 64-bit) Base address in the guest physical address space of the GIC virtual cpu interface register mappings. + + 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 | + + All distributor regs are (rw, 32-bit) + + 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 + 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 + Errors: + -ENODEV: Getting or setting this register is not yet supported + -EBUSY: One or more VCPUs are running + + 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 | + values: | reserved | cpu id | offset | + + All CPU interface regs are (rw, 32-bit) + + The offset specifies the offset from the "CPU interface base address" as + defined in the GICv2 specs. Getting or setting such a register has the + same effect as reading or writing the register on the actual hardware. + + The Active Priorities Registers APRn are implementation defined, so we set a + fixed format for our implementation that fits with the model of a "GICv2 + implementation without the security extensions" which we present to the + guest. This interface always exposes four register APR[0-3] describing the + maximum possible 128 preemption levels. The semantics of the register + indicate if any interrupts in a given preemption level are in the active + state by setting the corresponding bit. + + Thus, preemption level X has one or more active interrupts if and only if: + + APRn[X mod 32] == 0b1, where n = X / 32 + + Bits for undefined preemption levels are RAZ/WI. + + 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 diff --git a/arch/arm/include/uapi/asm/kvm.h b/arch/arm/include/uapi/asm/kvm.h index 76a7427..ef0c878 100644 --- a/arch/arm/include/uapi/asm/kvm.h +++ b/arch/arm/include/uapi/asm/kvm.h @@ -165,6 +165,12 @@ struct kvm_arch_memory_slot {

/* Device Control API: ARM VGIC */ #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_CPUID_SHIFT 32 +#define KVM_DEV_ARM_VGIC_CPUID_MASK (0xffULL << 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)

/* KVM_IRQ_LINE irq field index values */ #define KVM_ARM_IRQ_TYPE_SHIFT 24 diff --git a/virt/kvm/arm/vgic.c b/virt/kvm/arm/vgic.c index e2596f6..88599b5 100644 --- a/virt/kvm/arm/vgic.c +++ b/virt/kvm/arm/vgic.c @@ -589,6 +589,20 @@ static bool handle_mmio_sgi_reg(struct kvm_vcpu *vcpu, return false; }

+static bool handle_mmio_sgi_clear(struct kvm_vcpu *vcpu, + struct kvm_exit_mmio *mmio, + phys_addr_t offset) +{ + return false; +} + +static bool handle_mmio_sgi_set(struct kvm_vcpu *vcpu, + struct kvm_exit_mmio *mmio, + phys_addr_t offset) +{ + return false; +} + /* * I would have liked to use the kvm_bus_io_*() API instead, but it * cannot cope with banked registers (only the VM pointer is passed @@ -663,6 +677,16 @@ static const struct mmio_range vgic_dist_ranges[] = { .len = 4, .handle_mmio = handle_mmio_sgi_reg, }, + { + .base = GIC_DIST_SGI_PENDING_CLEAR, + .len = VGIC_NR_SGIS, + .handle_mmio = handle_mmio_sgi_clear, + }, + { + .base = GIC_DIST_SGI_PENDING_SET, + .len = VGIC_NR_SGIS, + .handle_mmio = handle_mmio_sgi_set, + }, {} };

@@ -1557,6 +1581,114 @@ int kvm_vgic_addr(struct kvm *kvm, unsigned long type, u64 *addr, bool write) return r; }

+static bool handle_cpu_mmio_misc(struct kvm_vcpu *vcpu, + struct kvm_exit_mmio *mmio, phys_addr_t offset) +{ + return true; +} + +static const struct mmio_range vgic_cpu_ranges[] = { + { + .base = GIC_CPU_CTRL, + .len = 12, + .handle_mmio = handle_cpu_mmio_misc, + }, + { + .base = GIC_CPU_ALIAS_BINPOINT, + .len = 4, + .handle_mmio = handle_cpu_mmio_misc, + }, + { + .base = GIC_CPU_ACTIVEPRIO, + .len = 16, + .handle_mmio = handle_cpu_mmio_misc, + }, + { + .base = GIC_CPU_IDENT, + .len = 4, + .handle_mmio = handle_cpu_mmio_misc, + }, +}; + +static int vgic_attr_regs_access(struct kvm_device *dev, + struct kvm_device_attr *attr, + u32 *reg, bool is_write) +{ + const struct mmio_range *r = NULL, *ranges; + phys_addr_t offset; + int ret, cpuid, c; + struct kvm_vcpu *vcpu, *tmp_vcpu; + struct vgic_dist *vgic; + struct kvm_exit_mmio mmio; + + offset = attr->attr & KVM_DEV_ARM_VGIC_OFFSET_MASK; + cpuid = (attr->attr & KVM_DEV_ARM_VGIC_CPUID_MASK) >> + KVM_DEV_ARM_VGIC_CPUID_SHIFT; + + mutex_lock(&dev->kvm->lock); + + if (cpuid >= atomic_read(&dev->kvm->online_vcpus)) { + ret = -EINVAL; + goto out; + } + + vcpu = kvm_get_vcpu(dev->kvm, cpuid); + vgic = &dev->kvm->arch.vgic; + + mmio.len = 4; + mmio.is_write = is_write; + if (is_write) + mmio_data_write(&mmio, ~0, *reg); + switch (attr->group) { + case KVM_DEV_ARM_VGIC_GRP_DIST_REGS: + mmio.phys_addr = vgic->vgic_dist_base + offset; + ranges = vgic_dist_ranges; + break; + case KVM_DEV_ARM_VGIC_GRP_CPU_REGS: + mmio.phys_addr = vgic->vgic_cpu_base + offset; + ranges = vgic_cpu_ranges; + break; + default: + BUG(); + } + r = find_matching_range(ranges, &mmio, offset); + + if (unlikely(!r || !r->handle_mmio)) { + ret = -ENXIO; + goto out; + } + + + spin_lock(&vgic->lock); + + /* + * Ensure that no other VCPU is running by checking the vcpu->cpu + * field. If no other VPCUs are running we can safely access the VGIC + * state, because even if another VPU is run after this point, that + * VCPU will not touch the vgic state, because it will block on + * getting the vgic->lock in kvm_vgic_sync_hwstate(). + */ + kvm_for_each_vcpu(c, tmp_vcpu, dev->kvm) { + if (unlikely(tmp_vcpu->cpu != -1)) { + ret = -EBUSY; + goto out_vgic_unlock; + } + } + + offset -= r->base; + r->handle_mmio(vcpu, &mmio, offset); + + if (!is_write) + *reg = mmio_data_read(&mmio, ~0); + + ret = 0; +out_vgic_unlock: + spin_unlock(&vgic->lock); +out: + mutex_unlock(&dev->kvm->lock); + return ret; +} + static int vgic_set_attr(struct kvm_device *dev, struct kvm_device_attr *attr) { int r; @@ -1573,6 +1705,18 @@ static int vgic_set_attr(struct kvm_device *dev, struct kvm_device_attr *attr) r = kvm_vgic_addr(dev->kvm, type, &addr, true); return (r == -ENODEV) ? -ENXIO : r; } + + case KVM_DEV_ARM_VGIC_GRP_DIST_REGS: + case KVM_DEV_ARM_VGIC_GRP_CPU_REGS: { + u32 __user *uaddr = (u32 __user *)(long)attr->addr; + u32 reg; + + if (get_user(reg, uaddr)) + return -EFAULT; + + return vgic_attr_regs_access(dev, attr, &reg, true); + } + }

return -ENXIO; @@ -1594,14 +1738,42 @@ static int vgic_get_attr(struct kvm_device *dev, struct kvm_device_attr *attr)

if (copy_to_user(uaddr, &addr, sizeof(addr))) return -EFAULT; + break; + } + + case KVM_DEV_ARM_VGIC_GRP_DIST_REGS: + case KVM_DEV_ARM_VGIC_GRP_CPU_REGS: { + u32 __user *uaddr = (u32 __user *)(long)attr->addr; + u32 reg = 0; + + r = vgic_attr_regs_access(dev, attr, &reg, false); + if (r) + return r; + r = put_user(reg, uaddr); + break; } + }

return r; }

+static int vgic_has_attr_regs(const struct mmio_range *ranges, + phys_addr_t offset) +{ + struct kvm_exit_mmio dev_attr_mmio; + + dev_attr_mmio.len = 4; + if (find_matching_range(ranges, &dev_attr_mmio, offset)) + return 0; + else + return -ENXIO; +} + static int vgic_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) { @@ -1610,6 +1782,12 @@ static int vgic_has_attr(struct kvm_device *dev, struct kvm_device_attr *attr) return 0; } break; + case KVM_DEV_ARM_VGIC_GRP_DIST_REGS: + offset = attr->attr & KVM_DEV_ARM_VGIC_OFFSET_MASK; + return vgic_has_attr_regs(vgic_dist_ranges, offset); + case KVM_DEV_ARM_VGIC_GRP_CPU_REGS: + offset = attr->attr & KVM_DEV_ARM_VGIC_OFFSET_MASK; + return vgic_has_attr_regs(vgic_cpu_ranges, offset); } return -ENXIO; }

To properly access the VGIC state from user space it is very unpractical to have to loop through all the LRs in all register access functions. Instead, support moving all pending state from LRs to the distributor, but leave active state LRs alone.

Note that to accurately present the active and pending state to VCPUs reading these distributor registers from a live VM, we would have to stop all other VPUs than the calling VCPU and ask each CPU to unqueue their LR state onto the distributor and add fields to track active state on the distributor side as well. We don't have any users of such functionality yet and there are other inaccuracies of the GIC emulation, so don't provide accurate synchronized access to this state just yet. However, when the time comes, having this function should help.

Signed-off-by: Christoffer Dall christoffer.dall@linaro.org --- Changelog[v4]: - Reworked vgic_unqueue_irqs to explicitly check for the active bit and to not use __test_and_clear_bit.

Changelog[v3]: - New patch in series

virt/kvm/arm/vgic.c | 86 +++++++++++++++++++++++++++++++++++++++++++++++++---- 1 file changed, 81 insertions(+), 5 deletions(-)

diff --git a/virt/kvm/arm/vgic.c b/virt/kvm/arm/vgic.c index 88599b5..8067e76 100644 --- a/virt/kvm/arm/vgic.c +++ b/virt/kvm/arm/vgic.c @@ -589,6 +589,78 @@ static bool handle_mmio_sgi_reg(struct kvm_vcpu *vcpu, return false; }

+#define LR_CPUID(lr) \ + (((lr) & GICH_LR_PHYSID_CPUID) >> GICH_LR_PHYSID_CPUID_SHIFT) +#define LR_IRQID(lr) \ + ((lr) & GICH_LR_VIRTUALID) + +static void vgic_retire_lr(int lr_nr, int irq, struct vgic_cpu *vgic_cpu) +{ + clear_bit(lr_nr, vgic_cpu->lr_used); + vgic_cpu->vgic_lr[lr_nr] &= ~GICH_LR_STATE; + vgic_cpu->vgic_irq_lr_map[irq] = LR_EMPTY; +} + +/** + * vgic_unqueue_irqs - move pending IRQs from LRs to the distributor + * @vgic_cpu: Pointer to the vgic_cpu struct holding the LRs + * + * Move any pending IRQs that have already been assigned to LRs back to the + * emulated distributor state so that the complete emulated state can be read + * from the main emulation structures without investigating the LRs. + * + * Note that IRQs in the active state in the LRs get their pending state moved + * to the distributor but the active state stays in the LRs, because we don't + * track the active state on the distributor side. + */ +static void vgic_unqueue_irqs(struct kvm_vcpu *vcpu) +{ + struct vgic_dist *dist = &vcpu->kvm->arch.vgic; + struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu; + int vcpu_id = vcpu->vcpu_id; + int i, irq, source_cpu; + u32 *lr; + + for_each_set_bit(i, vgic_cpu->lr_used, vgic_cpu->nr_lr) { + lr = &vgic_cpu->vgic_lr[i]; + irq = LR_IRQID(*lr); + source_cpu = LR_CPUID(*lr); + + /* + * There are three options for the state bits: + * + * 01: pending + * 10: active + * 11: pending and active + * + * If the LR holds only an active interrupt (not pending) then + * just leave it alone. + */ + if ((*lr & GICH_LR_STATE) == GICH_LR_ACTIVE_BIT) + continue; + + /* + * If the interrupt was only pending (not "active" or "pending + * and active") then we the pending state will get moved to + * the distributor and the LR does not hold any info and can + * be marked as free for other use. + */ + if ((*lr & GICH_LR_STATE) == GICH_LR_PENDING_BIT) + vgic_retire_lr(i, irq, vgic_cpu); + + /* + * Finally, reestablish the pending state on the distributor + * and the CPU interface. It may have already been pending, + * but that is fine, then we are only setting a few bits that + * were already set. + */ + vgic_dist_irq_set(vcpu, irq); + if (irq < VGIC_NR_SGIS) + dist->irq_sgi_sources[vcpu_id][irq] |= 1 << source_cpu; + vgic_update_state(vcpu->kvm); + } +} + static bool handle_mmio_sgi_clear(struct kvm_vcpu *vcpu, struct kvm_exit_mmio *mmio, phys_addr_t offset) @@ -848,8 +920,6 @@ static void vgic_update_state(struct kvm *kvm) } }

-#define LR_CPUID(lr) \ - (((lr) & GICH_LR_PHYSID_CPUID) >> GICH_LR_PHYSID_CPUID_SHIFT) #define MK_LR_PEND(src, irq) \ (GICH_LR_PENDING_BIT | ((src) << GICH_LR_PHYSID_CPUID_SHIFT) | (irq))

@@ -871,9 +941,7 @@ static void vgic_retire_disabled_irqs(struct kvm_vcpu *vcpu) int irq = vgic_cpu->vgic_lr[lr] & GICH_LR_VIRTUALID;

if (!vgic_irq_is_enabled(vcpu, irq)) { - vgic_cpu->vgic_irq_lr_map[irq] = LR_EMPTY; - clear_bit(lr, vgic_cpu->lr_used); - vgic_cpu->vgic_lr[lr] &= ~GICH_LR_STATE; + vgic_retire_lr(lr, irq, vgic_cpu); if (vgic_irq_is_active(vcpu, irq)) vgic_irq_clear_active(vcpu, irq); } @@ -1675,6 +1743,14 @@ static int vgic_attr_regs_access(struct kvm_device *dev, } }

+ /* + * Move all pending IRQs from the LRs on all VCPUs so the pending + * state can be properly represented in the register state accessible + * through this API. + */ + kvm_for_each_vcpu(c, tmp_vcpu, dev->kvm) + vgic_unqueue_irqs(tmp_vcpu); + offset -= r->base; r->handle_mmio(vcpu, &mmio, offset);

Implement support for the CPU interface register access driven by MMIO address offsets from the CPU interface base address. Useful for user space to support save/restore of the VGIC state.

This commit adds support only for the same logic as the current VGIC support, and no more. For example, the active priority registers are handled as RAZ/WI, just like setting priorities on the emulated distributor.

Acked-by: Marc Zyngier marc.zyngier@arm.com Signed-off-by: Christoffer Dall christoffer.dall@linaro.org --- virt/kvm/arm/vgic.c | 81 +++++++++++++++++++++++++++++++++++++++++++++++------ 1 file changed, 73 insertions(+), 8 deletions(-)

diff --git a/virt/kvm/arm/vgic.c b/virt/kvm/arm/vgic.c index 752f76c..977f479 100644 --- a/virt/kvm/arm/vgic.c +++ b/virt/kvm/arm/vgic.c @@ -71,6 +71,10 @@ #define VGIC_ADDR_UNDEF (-1) #define IS_VGIC_ADDR_UNDEF(_x) ((_x) == VGIC_ADDR_UNDEF)

+#define PRODUCT_ID_KVM 0x4b /* ASCII code K */ +#define IMPLEMENTER_ARM 0x43b +#define GICC_ARCH_VERSION_V2 0x2 + /* Physical address of vgic virtual cpu interface */ static phys_addr_t vgic_vcpu_base;

@@ -312,7 +316,7 @@ static bool handle_mmio_misc(struct kvm_vcpu *vcpu, u32 word_offset = offset & 3;

switch (offset & ~3) { - case 0: /* CTLR */ + case 0: /* GICD_CTLR */ reg = vcpu->kvm->arch.vgic.enabled; vgic_reg_access(mmio, &reg, word_offset, ACCESS_READ_VALUE | ACCESS_WRITE_VALUE); @@ -323,15 +327,15 @@ static bool handle_mmio_misc(struct kvm_vcpu *vcpu, } break;

- case 4: /* TYPER */ + case 4: /* GICD_TYPER */ reg = (atomic_read(&vcpu->kvm->online_vcpus) - 1) << 5; reg |= (VGIC_NR_IRQS >> 5) - 1; vgic_reg_access(mmio, &reg, word_offset, ACCESS_READ_VALUE | ACCESS_WRITE_IGNORED); break;

- case 8: /* IIDR */ - reg = 0x4B00043B; + case 8: /* GICD_IIDR */ + reg = (PRODUCT_ID_KVM << 24) | (IMPLEMENTER_ARM << 0); vgic_reg_access(mmio, &reg, word_offset, ACCESS_READ_VALUE | ACCESS_WRITE_IGNORED); break; @@ -1714,9 +1718,70 @@ int kvm_vgic_addr(struct kvm *kvm, unsigned long type, u64 *addr, bool write) static bool handle_cpu_mmio_misc(struct kvm_vcpu *vcpu, struct kvm_exit_mmio *mmio, phys_addr_t offset) { - return true; + struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu; + u32 reg, mask = 0, shift = 0; + bool updated = false; + + switch (offset & ~0x3) { + case GIC_CPU_CTRL: + mask = GICH_VMCR_CTRL_MASK; + shift = GICH_VMCR_CTRL_SHIFT; + break; + case GIC_CPU_PRIMASK: + mask = GICH_VMCR_PRIMASK_MASK; + shift = GICH_VMCR_PRIMASK_SHIFT; + break; + case GIC_CPU_BINPOINT: + mask = GICH_VMCR_BINPOINT_MASK; + shift = GICH_VMCR_BINPOINT_SHIFT; + break; + case GIC_CPU_ALIAS_BINPOINT: + mask = GICH_VMCR_ALIAS_BINPOINT_MASK; + shift = GICH_VMCR_ALIAS_BINPOINT_SHIFT; + break; + } + + if (!mmio->is_write) { + reg = (vgic_cpu->vgic_vmcr & mask) >> shift; + mmio_data_write(mmio, ~0, reg); + } else { + reg = mmio_data_read(mmio, ~0); + reg = (reg << shift) & mask; + if (reg != (vgic_cpu->vgic_vmcr & mask)) + updated = true; + vgic_cpu->vgic_vmcr &= ~mask; + vgic_cpu->vgic_vmcr |= reg; + } + return updated; +} + +static bool handle_mmio_abpr(struct kvm_vcpu *vcpu, + struct kvm_exit_mmio *mmio, phys_addr_t offset) +{ + return handle_cpu_mmio_misc(vcpu, mmio, GIC_CPU_ALIAS_BINPOINT); }

+static bool handle_cpu_mmio_ident(struct kvm_vcpu *vcpu, + struct kvm_exit_mmio *mmio, + phys_addr_t offset) +{ + u32 reg; + + if (mmio->is_write) + return false; + + /* GICC_IIDR */ + reg = (PRODUCT_ID_KVM << 20) | + (GICC_ARCH_VERSION_V2 << 16) | + (IMPLEMENTER_ARM << 0); + mmio_data_write(mmio, ~0, reg); + return false; +} + +/* + * CPU Interface Register accesses - these are not accessed by the VM, but by + * user space for saving and restoring VGIC state. + */ static const struct mmio_range vgic_cpu_ranges[] = { { .base = GIC_CPU_CTRL, @@ -1726,17 +1791,17 @@ static const struct mmio_range vgic_cpu_ranges[] = { { .base = GIC_CPU_ALIAS_BINPOINT, .len = 4, - .handle_mmio = handle_cpu_mmio_misc, + .handle_mmio = handle_mmio_abpr, }, { .base = GIC_CPU_ACTIVEPRIO, .len = 16, - .handle_mmio = handle_cpu_mmio_misc, + .handle_mmio = handle_mmio_raz_wi, }, { .base = GIC_CPU_IDENT, .len = 4, - .handle_mmio = handle_cpu_mmio_misc, + .handle_mmio = handle_cpu_mmio_ident, }, };