This patch includes the SVE register IDs in the list returned by
KVM_GET_REG_LIST, as appropriate.
On a non-SVE-enabled vcpu, no new IDs are added.
On an SVE-enabled vcpu, IDs for the FPSIMD V-registers are removed
from the list, since userspace is required to access the Z-
registers instead to access their context. For the variably-sized
SVE registers, the appropriate set of slice IDs are enumerated,
depending on the maximum vector length for the vcpu.
Signed-off-by: Dave Martin <Dave.Martin at arm.com>
---
Changes since v4:
* Drop KVM_SVE_SLICES(), which is no longer used due to the dropping of
register multi-slice support from the series.
* Drop register multi-slice support.
---
arch/arm64/kvm/guest.c | 51 ++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 51 insertions(+)
diff --git a/arch/arm64/kvm/guest.c b/arch/arm64/kvm/guest.c
index 8cfa889..4a2ad60 100644
--- a/arch/arm64/kvm/guest.c
+++ b/arch/arm64/kvm/guest.c
@@ -366,6 +366,14 @@ static int copy_core_reg_indices(const struct kvm_vcpu *vcpu,
continue;
}
+ /*
+ * 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 (uind) {
if (put_user(reg, *uind))
return -EFAULT;
@@ -436,6 +444,44 @@ 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)
+{
+ /* Only the first slice ever exists, for now */
+ const unsigned int slices = 1;
+
+ if (!vcpu_has_sve(vcpu))
+ return 0;
+
+ return slices * (SVE_NUM_PREGS + SVE_NUM_ZREGS + 1 /* FFR */);
+}
+
+static int copy_sve_reg_indices(const struct kvm_vcpu *vcpu, u64 __user **uind)
+{
+ /* Only the first slice ever exists, for now */
+ const unsigned int slices = 1;
+ unsigned int i, n;
+
+ if (!vcpu_has_sve(vcpu))
+ return 0;
+
+ for (i = 0; i < slices; i++) {
+ for (n = 0; n < SVE_NUM_ZREGS; n++) {
+ if (put_user(KVM_REG_ARM64_SVE_ZREG(n, i), (*uind)++))
+ return -EFAULT;
+ }
+
+ for (n = 0; n < SVE_NUM_PREGS; n++) {
+ if (put_user(KVM_REG_ARM64_SVE_PREG(n, i), (*uind)++))
+ return -EFAULT;
+ }
+
+ if (put_user(KVM_REG_ARM64_SVE_FFR(i), (*uind)++))
+ return -EFAULT;
+ }
+
+ return 0;
+}
+
/**
* kvm_arm_num_regs - how many registers do we present via KVM_GET_ONE_REG
*
@@ -446,6 +492,7 @@ unsigned long kvm_arm_num_regs(struct kvm_vcpu *vcpu)
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;
@@ -466,6 +513,10 @@ int kvm_arm_copy_reg_indices(struct kvm_vcpu *vcpu, u64 __user *uindices)
if (ret < 0)
return ret;
+ ret = copy_sve_reg_indices(vcpu, &uindices);
+ if (ret)
+ return ret;
+
ret = kvm_arm_copy_fw_reg_indices(vcpu, uindices);
if (ret)
return ret;
--
2.1.4
