This patch prints out some information about the SVE configuration
when --show-reg=list is passed.
This is development hack only (as well as being an abuse of the
purpose of that option).
Signed-off-by: Dave Martin <Dave.Martin@xxxxxxx>
---
arm/kvm-cpu.c | 111 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 110 insertions(+), 1 deletion(-)
diff --git a/arm/kvm-cpu.c b/arm/kvm-cpu.c
index 38a071b..80e7b79 100644
--- a/arm/kvm-cpu.c
+++ b/arm/kvm-cpu.c
@@ -1,3 +1,4 @@
+#include <assert.h>
#include <errno.h>
#include <stddef.h>
#include <stdio.h>
@@ -48,6 +49,112 @@ error:
return ret;
}
+static int kvm_show_sve_info(struct kvm_cpu const *vcpu)
+{
+ int ret = 0;
+ u64 val;
+ struct kvm_one_reg r;
+ int have_sve;
+ u64 vls[9];
+ unsigned int i;
+
+ r.addr = (u64)&val;
+
+ r.id = ARM64_SYS_REG(3, 0, 0, 4, 0); /* ID_AA64PFR0_EL1 */
+ assert((r.id & KVM_REG_SIZE_MASK) == KVM_REG_SIZE_U64);
+ if (ioctl(vcpu->vcpu_fd, KVM_GET_ONE_REG, &r)) {
+ perror("KVM_GET_ONE_REG(ID_AA64PFR0_EL1)");
+ goto error;
+ }
+
+ printf("ID_AA64PFR0_EL1:\t0x%lx\n", (unsigned long)val);
+
+ have_sve = !!((val >> 32) & 0xf);
+
+ r.id = ARM64_SYS_REG(3, 0, 0, 4, 4);
+ if (ioctl(vcpu->vcpu_fd, KVM_GET_ONE_REG, &r)) {
+ if (errno != ENOENT || have_sve) {
+ perror("KVM_GET_ONE_REG(ID_AA64ZFR0_EL1)");
+ ret = -1;
+ }
+ } else {
+ if (!have_sve) {
+ puts("ID_AA64ZFR0_EL1 unexpectedly present");
+ ret = -1;
+ }
+
+ printf("ID_AA64ZFR0_EL1:\t0x%lx\n", (unsigned long)val);
+ }
+
+ r.id = ARM64_SYS_REG(3, 0, 1, 2, 0);
+ if (ioctl(vcpu->vcpu_fd, KVM_GET_ONE_REG, &r)) {
+ if (errno != ENOENT || have_sve) {
+ perror("KVM_GET_ONE_REG(ZCR_EL1)");
+ ret = -1;
+ }
+ } else {
+ if (!have_sve) {
+ puts("ZCR_EL1 unexpectedly present");
+ ret = -1;
+ }
+
+ printf("ZCR_EL1:\t0x%lx\n", (unsigned long)val);
+ }
+
+ r.addr = (u64)&vls;
+ r.id = KVM_REG_ARM64_SVE_VLS;
+ assert(8 * (sizeof(vls) - sizeof(*vls)) == 512 &&
+ (r.id & KVM_REG_SIZE_MASK) == KVM_REG_SIZE_U512);
+
+ /*
+ * Write some canary data so we can see that the kernel writes
+ * the expected amount:
+ */
+ for (i = 0; i < sizeof(vls) / sizeof(*vls); ++i)
+ vls[i] = -7;
+
+ if (ioctl(vcpu->vcpu_fd, KVM_GET_ONE_REG, &r)) {
+ if (errno != ENOENT || have_sve) {
+ perror("KVM_GET_ONE_REG(KVM_REG_ARM64_SVE_VLS)");
+ ret = -1;
+ }
+ } else {
+ char const *prefix = "";
+
+ if (!have_sve) {
+ puts("KVM_REG_ARM64_SVE_VLS unexpectedly present");
+ ret = -1;
+ }
+
+ if (vls[7] == (u64)-7) {
+ puts("KVM_REG_ARM64_SVE_VLS short read?");
+ ret = -1;
+ }
+
+ if (vls[8] != (u64)-7) {
+ puts("KVM_REG_ARM64_SVE_VLS overrun?");
+ ret = -1;
+ }
+
+ fputs("SVE VQs: ", stdout);
+
+ for (i = 0; i < 512; ++i)
+ if ((vls[i / 64] >> (i % 64)) & 1) {
+ printf("%s%lu", prefix, (unsigned long)i + 1);
+ prefix = ",";
+ }
+
+ putchar('\n');
+ }
+
+ fflush(stdout);
+
+ return ret;
+
+error:
+ return -1;
+}
+
static int debug_fd;
void kvm_cpu__set_debug_fd(int fd)
@@ -156,8 +263,10 @@ struct kvm_cpu *kvm_cpu__arch_init(struct kvm *kvm, unsigned long cpu_id)
if (err || target->init(vcpu))
die("Unable to initialise vcpu");
- if (kvm->cfg.arch.show_reg_list)
+ if (kvm->cfg.arch.show_reg_list) {
+ kvm_show_sve_info(vcpu);
kvm_show_reg_list(vcpu);
+ }
coalesced_offset = ioctl(kvm->sys_fd, KVM_CHECK_EXTENSION,
KVM_CAP_COALESCED_MMIO);
--
2.1.4
_______________________________________________
kvmarm mailing list
kvmarm@xxxxxxxxxxxxxxxxxxxxx
https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
