1 files changed, 383 insertions, 32 deletions

diff --git a/arch/arm64/kvm/guest.c b/arch/arm64/kvm/guest.c
index dd436a50fce7..3ae2f82fca46 100644
--- a/arch/arm64/kvm/guest.c
+++ b/arch/arm64/kvm/guest.c
@@ -19,18 +19,25 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
+#include <linux/bits.h>
 #include <linux/errno.h>
 #include <linux/err.h>
+#include <linux/nospec.h>
 #include <linux/kvm_host.h>
 #include <linux/module.h>
+#include <linux/stddef.h>
+#include <linux/string.h>
 #include <linux/vmalloc.h>
 #include <linux/fs.h>
 #include <kvm/arm_psci.h>
 #include <asm/cputype.h>
 #include <linux/uaccess.h>
+#include <asm/fpsimd.h>
 #include <asm/kvm.h>
 #include <asm/kvm_emulate.h>
 #include <asm/kvm_coproc.h>
+#include <asm/kvm_host.h>
+#include <asm/sigcontext.h>
 
 #include "trace.h"
 
@@ -52,12 +59,19 @@ int kvm_arch_vcpu_setup(struct kvm_vcpu *vcpu)
 	return 0;
 }
 
+static bool core_reg_offset_is_vreg(u64 off)
+{
+	return off >= KVM_REG_ARM_CORE_REG(fp_regs.vregs) &&
+		off < KVM_REG_ARM_CORE_REG(fp_regs.fpsr);
+}
+
 static u64 core_reg_offset_from_id(u64 id)
 {
 	return id & ~(KVM_REG_ARCH_MASK | KVM_REG_SIZE_MASK | KVM_REG_ARM_CORE);
 }
 
-static int validate_core_offset(const struct kvm_one_reg *reg)
+static int validate_core_offset(const struct kvm_vcpu *vcpu,
+				const struct kvm_one_reg *reg)
 {
 	u64 off = core_reg_offset_from_id(reg->id);
 	int size;
@@ -89,11 +103,19 @@ static int validate_core_offset(const struct kvm_one_reg *reg)
 		return -EINVAL;
 	}
 
-	if (KVM_REG_SIZE(reg->id) == size &&
-	    IS_ALIGNED(off, size / sizeof(__u32)))
-		return 0;
+	if (KVM_REG_SIZE(reg->id) != size ||
+	    !IS_ALIGNED(off, size / sizeof(__u32)))
+		return -EINVAL;
 
-	return -EINVAL;
+	/*
+	 * The KVM_REG_ARM64_SVE regs must be used instead of
+	 * KVM_REG_ARM_CORE for accessing the FPSIMD V-registers on
+	 * SVE-enabled vcpus:
+	 */
+	if (vcpu_has_sve(vcpu) && core_reg_offset_is_vreg(off))
+		return -EINVAL;
+
+	return 0;
 }
 
 static int get_core_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
@@ -115,7 +137,7 @@ static int get_core_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
 	    (off + (KVM_REG_SIZE(reg->id) / sizeof(__u32))) >= nr_regs)
 		return -ENOENT;
 
-	if (validate_core_offset(reg))
+	if (validate_core_offset(vcpu, reg))
 		return -EINVAL;
 
 	if (copy_to_user(uaddr, ((u32 *)regs) + off, KVM_REG_SIZE(reg->id)))
@@ -140,7 +162,7 @@ static int set_core_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
 	    (off + (KVM_REG_SIZE(reg->id) / sizeof(__u32))) >= nr_regs)
 		return -ENOENT;
 
-	if (validate_core_offset(reg))
+	if (validate_core_offset(vcpu, reg))
 		return -EINVAL;
 
 	if (KVM_REG_SIZE(reg->id) > sizeof(tmp))
@@ -183,6 +205,239 @@ out:
 	return err;
 }
 
+#define vq_word(vq) (((vq) - SVE_VQ_MIN) / 64)
+#define vq_mask(vq) ((u64)1 << ((vq) - SVE_VQ_MIN) % 64)
+
+static bool vq_present(
+	const u64 (*const vqs)[KVM_ARM64_SVE_VLS_WORDS],
+	unsigned int vq)
+{
+	return (*vqs)[vq_word(vq)] & vq_mask(vq);
+}
+
+static int get_sve_vls(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
+{
+	unsigned int max_vq, vq;
+	u64 vqs[KVM_ARM64_SVE_VLS_WORDS];
+
+	if (!vcpu_has_sve(vcpu))
+		return -ENOENT;
+
+	if (WARN_ON(!sve_vl_valid(vcpu->arch.sve_max_vl)))
+		return -EINVAL;
+
+	memset(vqs, 0, sizeof(vqs));
+
+	max_vq = sve_vq_from_vl(vcpu->arch.sve_max_vl);
+	for (vq = SVE_VQ_MIN; vq <= max_vq; ++vq)
+		if (sve_vq_available(vq))
+			vqs[vq_word(vq)] |= vq_mask(vq);
+
+	if (copy_to_user((void __user *)reg->addr, vqs, sizeof(vqs)))
+		return -EFAULT;
+
+	return 0;
+}
+
+static int set_sve_vls(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
+{
+	unsigned int max_vq, vq;
+	u64 vqs[KVM_ARM64_SVE_VLS_WORDS];
+
+	if (!vcpu_has_sve(vcpu))
+		return -ENOENT;
+
+	if (kvm_arm_vcpu_sve_finalized(vcpu))
+		return -EPERM; /* too late! */
+
+	if (WARN_ON(vcpu->arch.sve_state))
+		return -EINVAL;
+
+	if (copy_from_user(vqs, (const void __user *)reg->addr, sizeof(vqs)))
+		return -EFAULT;
+
+	max_vq = 0;
+	for (vq = SVE_VQ_MIN; vq <= SVE_VQ_MAX; ++vq)
+		if (vq_present(&vqs, vq))
+			max_vq = vq;
+
+	if (max_vq > sve_vq_from_vl(kvm_sve_max_vl))
+		return -EINVAL;
+
+	/*
+	 * Vector lengths supported by the host can't currently be
+	 * hidden from the guest individually: instead we can only set a
+	 * maxmium via ZCR_EL2.LEN.  So, make sure the available vector
+	 * lengths match the set requested exactly up to the requested
+	 * maximum:
+	 */
+	for (vq = SVE_VQ_MIN; vq <= max_vq; ++vq)
+		if (vq_present(&vqs, vq) != sve_vq_available(vq))
+			return -EINVAL;
+
+	/* Can't run with no vector lengths at all: */
+	if (max_vq < SVE_VQ_MIN)
+		return -EINVAL;
+
+	/* vcpu->arch.sve_state will be alloc'd by kvm_vcpu_finalize_sve() */
+	vcpu->arch.sve_max_vl = sve_vl_from_vq(max_vq);
+
+	return 0;
+}
+
+#define SVE_REG_SLICE_SHIFT	0
+#define SVE_REG_SLICE_BITS	5
+#define SVE_REG_ID_SHIFT	(SVE_REG_SLICE_SHIFT + SVE_REG_SLICE_BITS)
+#define SVE_REG_ID_BITS		5
+
+#define SVE_REG_SLICE_MASK					\
+	GENMASK(SVE_REG_SLICE_SHIFT + SVE_REG_SLICE_BITS - 1,	\
+		SVE_REG_SLICE_SHIFT)
+#define SVE_REG_ID_MASK							\
+	GENMASK(SVE_REG_ID_SHIFT + SVE_REG_ID_BITS - 1, SVE_REG_ID_SHIFT)
+
+#define SVE_NUM_SLICES (1 << SVE_REG_SLICE_BITS)
+
+#define KVM_SVE_ZREG_SIZE KVM_REG_SIZE(KVM_REG_ARM64_SVE_ZREG(0, 0))
+#define KVM_SVE_PREG_SIZE KVM_REG_SIZE(KVM_REG_ARM64_SVE_PREG(0, 0))
+
+/*
+ * Number of register slices required to cover each whole SVE register.
+ * NOTE: Only the first slice every exists, for now.
+ * If you are tempted to modify this, you must also rework sve_reg_to_region()
+ * to match:
+ */
+#define vcpu_sve_slices(vcpu) 1
+
+/* Bounds of a single SVE register slice within vcpu->arch.sve_state */
+struct sve_state_reg_region {
+	unsigned int koffset;	/* offset into sve_state in kernel memory */
+	unsigned int klen;	/* length in kernel memory */
+	unsigned int upad;	/* extra trailing padding in user memory */
+};
+
+/*
+ * Validate SVE register ID and get sanitised bounds for user/kernel SVE
+ * register copy
+ */
+static int sve_reg_to_region(struct sve_state_reg_region *region,
+			     struct kvm_vcpu *vcpu,
+			     const struct kvm_one_reg *reg)
+{
+	/* reg ID ranges for Z- registers */
+	const u64 zreg_id_min = KVM_REG_ARM64_SVE_ZREG(0, 0);
+	const u64 zreg_id_max = KVM_REG_ARM64_SVE_ZREG(SVE_NUM_ZREGS - 1,
+						       SVE_NUM_SLICES - 1);
+
+	/* reg ID ranges for P- registers and FFR (which are contiguous) */
+	const u64 preg_id_min = KVM_REG_ARM64_SVE_PREG(0, 0);
+	const u64 preg_id_max = KVM_REG_ARM64_SVE_FFR(SVE_NUM_SLICES - 1);
+
+	unsigned int vq;
+	unsigned int reg_num;
+
+	unsigned int reqoffset, reqlen; /* User-requested offset and length */
+	unsigned int maxlen; /* Maxmimum permitted length */
+
+	size_t sve_state_size;
+
+	const u64 last_preg_id = KVM_REG_ARM64_SVE_PREG(SVE_NUM_PREGS - 1,
+							SVE_NUM_SLICES - 1);
+
+	/* Verify that the P-regs and FFR really do have contiguous IDs: */
+	BUILD_BUG_ON(KVM_REG_ARM64_SVE_FFR(0) != last_preg_id + 1);
+
+	/* Verify that we match the UAPI header: */
+	BUILD_BUG_ON(SVE_NUM_SLICES != KVM_ARM64_SVE_MAX_SLICES);
+
+	reg_num = (reg->id & SVE_REG_ID_MASK) >> SVE_REG_ID_SHIFT;
+
+	if (reg->id >= zreg_id_min && reg->id <= zreg_id_max) {
+		if (!vcpu_has_sve(vcpu) || (reg->id & SVE_REG_SLICE_MASK) > 0)
+			return -ENOENT;
+
+		vq = sve_vq_from_vl(vcpu->arch.sve_max_vl);
+
+		reqoffset = SVE_SIG_ZREG_OFFSET(vq, reg_num) -
+				SVE_SIG_REGS_OFFSET;
+		reqlen = KVM_SVE_ZREG_SIZE;
+		maxlen = SVE_SIG_ZREG_SIZE(vq);
+	} else if (reg->id >= preg_id_min && reg->id <= preg_id_max) {
+		if (!vcpu_has_sve(vcpu) || (reg->id & SVE_REG_SLICE_MASK) > 0)
+			return -ENOENT;
+
+		vq = sve_vq_from_vl(vcpu->arch.sve_max_vl);
+
+		reqoffset = SVE_SIG_PREG_OFFSET(vq, reg_num) -
+				SVE_SIG_REGS_OFFSET;
+		reqlen = KVM_SVE_PREG_SIZE;
+		maxlen = SVE_SIG_PREG_SIZE(vq);
+	} else {
+		return -EINVAL;
+	}
+
+	sve_state_size = vcpu_sve_state_size(vcpu);
+	if (WARN_ON(!sve_state_size))
+		return -EINVAL;
+
+	region->koffset = array_index_nospec(reqoffset, sve_state_size);
+	region->klen = min(maxlen, reqlen);
+	region->upad = reqlen - region->klen;
+
+	return 0;
+}
+
+static int get_sve_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
+{
+	int ret;
+	struct sve_state_reg_region region;
+	char __user *uptr = (char __user *)reg->addr;
+
+	/* Handle the KVM_REG_ARM64_SVE_VLS pseudo-reg as a special case: */
+	if (reg->id == KVM_REG_ARM64_SVE_VLS)
+		return get_sve_vls(vcpu, reg);
+
+	/* Try to interpret reg ID as an architectural SVE register... */
+	ret = sve_reg_to_region(&region, vcpu, reg);
+	if (ret)
+		return ret;
+
+	if (!kvm_arm_vcpu_sve_finalized(vcpu))
+		return -EPERM;
+
+	if (copy_to_user(uptr, vcpu->arch.sve_state + region.koffset,
+			 region.klen) ||
+	    clear_user(uptr + region.klen, region.upad))
+		return -EFAULT;
+
+	return 0;
+}
+
+static int set_sve_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
+{
+	int ret;
+	struct sve_state_reg_region region;
+	const char __user *uptr = (const char __user *)reg->addr;
+
+	/* Handle the KVM_REG_ARM64_SVE_VLS pseudo-reg as a special case: */
+	if (reg->id == KVM_REG_ARM64_SVE_VLS)
+		return set_sve_vls(vcpu, reg);
+
+	/* Try to interpret reg ID as an architectural SVE register... */
+	ret = sve_reg_to_region(&region, vcpu, reg);
+	if (ret)
+		return ret;
+
+	if (!kvm_arm_vcpu_sve_finalized(vcpu))
+		return -EPERM;
+
+	if (copy_from_user(vcpu->arch.sve_state + region.koffset, uptr,
+			   region.klen))
+		return -EFAULT;
+
+	return 0;
+}
+
 int kvm_arch_vcpu_ioctl_get_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs)
 {
 	return -EINVAL;
@@ -193,9 +448,37 @@ int kvm_arch_vcpu_ioctl_set_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs)
 	return -EINVAL;
 }
 
-static unsigned long num_core_regs(void)
+static int copy_core_reg_indices(const struct kvm_vcpu *vcpu,
+				 u64 __user *uindices)
+{
+	unsigned int i;
+	int n = 0;
+	const u64 core_reg = KVM_REG_ARM64 | KVM_REG_SIZE_U64 | KVM_REG_ARM_CORE;
+
+	for (i = 0; i < sizeof(struct kvm_regs) / sizeof(__u32); i++) {
+		/*
+		 * The KVM_REG_ARM64_SVE regs must be used instead of
+		 * KVM_REG_ARM_CORE for accessing the FPSIMD V-registers on
+		 * SVE-enabled vcpus:
+		 */
+		if (vcpu_has_sve(vcpu) && core_reg_offset_is_vreg(i))
+			continue;
+
+		if (uindices) {
+			if (put_user(core_reg | i, uindices))
+				return -EFAULT;
+			uindices++;
+		}
+
+		n++;
+	}
+
+	return n;
+}
+
+static unsigned long num_core_regs(const struct kvm_vcpu *vcpu)
 {
-	return sizeof(struct kvm_regs) / sizeof(__u32);
+	return copy_core_reg_indices(vcpu, NULL);
 }
 
 /**
@@ -251,6 +534,67 @@ static int get_timer_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
 	return copy_to_user(uaddr, &val, KVM_REG_SIZE(reg->id)) ? -EFAULT : 0;
 }
 
+static unsigned long num_sve_regs(const struct kvm_vcpu *vcpu)
+{
+	const unsigned int slices = vcpu_sve_slices(vcpu);
+
+	if (!vcpu_has_sve(vcpu))
+		return 0;
+
+	/* Policed by KVM_GET_REG_LIST: */
+	WARN_ON(!kvm_arm_vcpu_sve_finalized(vcpu));
+
+	return slices * (SVE_NUM_PREGS + SVE_NUM_ZREGS + 1 /* FFR */)
+		+ 1; /* KVM_REG_ARM64_SVE_VLS */
+}
+
+static int copy_sve_reg_indices(const struct kvm_vcpu *vcpu,
+				u64 __user *uindices)
+{
+	const unsigned int slices = vcpu_sve_slices(vcpu);
+	u64 reg;
+	unsigned int i, n;
+	int num_regs = 0;
+
+	if (!vcpu_has_sve(vcpu))
+		return 0;
+
+	/* Policed by KVM_GET_REG_LIST: */
+	WARN_ON(!kvm_arm_vcpu_sve_finalized(vcpu));
+
+	/*
+	 * Enumerate this first, so that userspace can save/restore in
+	 * the order reported by KVM_GET_REG_LIST:
+	 */
+	reg = KVM_REG_ARM64_SVE_VLS;
+	if (put_user(reg, uindices++))
+		return -EFAULT;
+	++num_regs;
+
+	for (i = 0; i < slices; i++) {
+		for (n = 0; n < SVE_NUM_ZREGS; n++) {
+			reg = KVM_REG_ARM64_SVE_ZREG(n, i);
+			if (put_user(reg, uindices++))
+				return -EFAULT;
+			num_regs++;
+		}
+
+		for (n = 0; n < SVE_NUM_PREGS; n++) {
+			reg = KVM_REG_ARM64_SVE_PREG(n, i);
+			if (put_user(reg, uindices++))
+				return -EFAULT;
+			num_regs++;
+		}
+
+		reg = KVM_REG_ARM64_SVE_FFR(i);
+		if (put_user(reg, uindices++))
+			return -EFAULT;
+		num_regs++;
+	}
+
+	return num_regs;
+}
+
 /**
  * kvm_arm_num_regs - how many registers do we present via KVM_GET_ONE_REG
  *
@@ -258,8 +602,15 @@ static int get_timer_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
  */
 unsigned long kvm_arm_num_regs(struct kvm_vcpu *vcpu)
 {
-	return num_core_regs() + kvm_arm_num_sys_reg_descs(vcpu)
-		+ kvm_arm_get_fw_num_regs(vcpu)	+ NUM_TIMER_REGS;
+	unsigned long res = 0;
+
+	res += num_core_regs(vcpu);
+	res += num_sve_regs(vcpu);
+	res += kvm_arm_num_sys_reg_descs(vcpu);
+	res += kvm_arm_get_fw_num_regs(vcpu);
+	res += NUM_TIMER_REGS;
+
+	return res;
 }
 
 /**
@@ -269,23 +620,25 @@ unsigned long kvm_arm_num_regs(struct kvm_vcpu *vcpu)
  */
 int kvm_arm_copy_reg_indices(struct kvm_vcpu *vcpu, u64 __user *uindices)
 {
-	unsigned int i;
-	const u64 core_reg = KVM_REG_ARM64 | KVM_REG_SIZE_U64 | KVM_REG_ARM_CORE;
 	int ret;
 
-	for (i = 0; i < sizeof(struct kvm_regs) / sizeof(__u32); i++) {
-		if (put_user(core_reg | i, uindices))
-			return -EFAULT;
-		uindices++;
-	}
+	ret = copy_core_reg_indices(vcpu, uindices);
+	if (ret < 0)
+		return ret;
+	uindices += ret;
+
+	ret = copy_sve_reg_indices(vcpu, uindices);
+	if (ret < 0)
+		return ret;
+	uindices += ret;
 
 	ret = kvm_arm_copy_fw_reg_indices(vcpu, uindices);
-	if (ret)
+	if (ret < 0)
 		return ret;
 	uindices += kvm_arm_get_fw_num_regs(vcpu);
 
 	ret = copy_timer_indices(vcpu, uindices);
-	if (ret)
+	if (ret < 0)
 		return ret;
 	uindices += NUM_TIMER_REGS;
 
@@ -298,12 +651,11 @@ int kvm_arm_get_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
 	if ((reg->id & ~KVM_REG_SIZE_MASK) >> 32 != KVM_REG_ARM64 >> 32)
 		return -EINVAL;
 
-	/* Register group 16 means we want a core register. */
-	if ((reg->id & KVM_REG_ARM_COPROC_MASK) == KVM_REG_ARM_CORE)
-		return get_core_reg(vcpu, reg);
-
-	if ((reg->id & KVM_REG_ARM_COPROC_MASK) == KVM_REG_ARM_FW)
-		return kvm_arm_get_fw_reg(vcpu, reg);
+	switch (reg->id & KVM_REG_ARM_COPROC_MASK) {
+	case KVM_REG_ARM_CORE:	return get_core_reg(vcpu, reg);
+	case KVM_REG_ARM_FW:	return kvm_arm_get_fw_reg(vcpu, reg);
+	case KVM_REG_ARM64_SVE:	return get_sve_reg(vcpu, reg);
+	}
 
 	if (is_timer_reg(reg->id))
 		return get_timer_reg(vcpu, reg);
@@ -317,12 +669,11 @@ int kvm_arm_set_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
 	if ((reg->id & ~KVM_REG_SIZE_MASK) >> 32 != KVM_REG_ARM64 >> 32)
 		return -EINVAL;
 
-	/* Register group 16 means we set a core register. */
-	if ((reg->id & KVM_REG_ARM_COPROC_MASK) == KVM_REG_ARM_CORE)
-		return set_core_reg(vcpu, reg);
-
-	if ((reg->id & KVM_REG_ARM_COPROC_MASK) == KVM_REG_ARM_FW)
-		return kvm_arm_set_fw_reg(vcpu, reg);
+	switch (reg->id & KVM_REG_ARM_COPROC_MASK) {
+	case KVM_REG_ARM_CORE:	return set_core_reg(vcpu, reg);
+	case KVM_REG_ARM_FW:	return kvm_arm_set_fw_reg(vcpu, reg);
+	case KVM_REG_ARM64_SVE:	return set_sve_reg(vcpu, reg);
+	}
 
 	if (is_timer_reg(reg->id))
 		return set_timer_reg(vcpu, reg);