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Diffstat (limited to 'target/arm/kvm64.c')
-rw-r--r--target/arm/kvm64.c47
1 files changed, 13 insertions, 34 deletions
diff --git a/target/arm/kvm64.c b/target/arm/kvm64.c
index 363032da90..ff8f65da22 100644
--- a/target/arm/kvm64.c
+++ b/target/arm/kvm64.c
@@ -574,6 +574,8 @@ bool kvm_arm_get_host_cpu_features(ARMHostCPUFeatures *ahcf)
     } else {
         err |= read_sys_reg64(fdarray[2], &ahcf->isar.id_aa64pfr1,
                               ARM64_SYS_REG(3, 0, 0, 4, 1));
+        err |= read_sys_reg64(fdarray[2], &ahcf->isar.id_aa64smfr0,
+                              ARM64_SYS_REG(3, 0, 0, 4, 5));
         err |= read_sys_reg64(fdarray[2], &ahcf->isar.id_aa64dfr0,
                               ARM64_SYS_REG(3, 0, 0, 5, 0));
         err |= read_sys_reg64(fdarray[2], &ahcf->isar.id_aa64dfr1,
@@ -682,10 +684,11 @@ bool kvm_arm_get_host_cpu_features(ARMHostCPUFeatures *ahcf)
         ahcf->isar.id_aa64pfr0 = t;
 
         /*
-         * Before v5.1, KVM did not support SVE and did not expose
-         * ID_AA64ZFR0_EL1 even as RAZ.  After v5.1, KVM still does
-         * not expose the register to "user" requests like this
-         * unless the host supports SVE.
+         * There is a range of kernels between kernel commit 73433762fcae
+         * and f81cb2c3ad41 which have a bug where the kernel doesn't expose
+         * SYS_ID_AA64ZFR0_EL1 via the ONE_REG API unless the VM has enabled
+         * SVE support, so we only read it here, rather than together with all
+         * the other ID registers earlier.
          */
         err |= read_sys_reg64(fdarray[2], &ahcf->isar.id_aa64zfr0,
                               ARM64_SYS_REG(3, 0, 0, 4, 4));
@@ -760,15 +763,13 @@ bool kvm_arm_steal_time_supported(void)
 
 QEMU_BUILD_BUG_ON(KVM_ARM64_SVE_VQ_MIN != 1);
 
-void kvm_arm_sve_get_vls(CPUState *cs, unsigned long *map)
+uint32_t kvm_arm_sve_get_vls(CPUState *cs)
 {
     /* Only call this function if kvm_arm_sve_supported() returns true. */
     static uint64_t vls[KVM_ARM64_SVE_VLS_WORDS];
     static bool probed;
     uint32_t vq = 0;
-    int i, j;
-
-    bitmap_zero(map, ARM_MAX_VQ);
+    int i;
 
     /*
      * KVM ensures all host CPUs support the same set of vector lengths.
@@ -809,46 +810,24 @@ void kvm_arm_sve_get_vls(CPUState *cs, unsigned long *map)
         if (vq > ARM_MAX_VQ) {
             warn_report("KVM supports vector lengths larger than "
                         "QEMU can enable");
+            vls[0] &= MAKE_64BIT_MASK(0, ARM_MAX_VQ);
         }
     }
 
-    for (i = 0; i < KVM_ARM64_SVE_VLS_WORDS; ++i) {
-        if (!vls[i]) {
-            continue;
-        }
-        for (j = 1; j <= 64; ++j) {
-            vq = j + i * 64;
-            if (vq > ARM_MAX_VQ) {
-                return;
-            }
-            if (vls[i] & (1UL << (j - 1))) {
-                set_bit(vq - 1, map);
-            }
-        }
-    }
+    return vls[0];
 }
 
 static int kvm_arm_sve_set_vls(CPUState *cs)
 {
-    uint64_t vls[KVM_ARM64_SVE_VLS_WORDS] = {0};
+    ARMCPU *cpu = ARM_CPU(cs);
+    uint64_t vls[KVM_ARM64_SVE_VLS_WORDS] = { cpu->sve_vq_map };
     struct kvm_one_reg reg = {
         .id = KVM_REG_ARM64_SVE_VLS,
         .addr = (uint64_t)&vls[0],
     };
-    ARMCPU *cpu = ARM_CPU(cs);
-    uint32_t vq;
-    int i, j;
 
     assert(cpu->sve_max_vq <= KVM_ARM64_SVE_VQ_MAX);
 
-    for (vq = 1; vq <= cpu->sve_max_vq; ++vq) {
-        if (test_bit(vq - 1, cpu->sve_vq_map)) {
-            i = (vq - 1) / 64;
-            j = (vq - 1) % 64;
-            vls[i] |= 1UL << j;
-        }
-    }
-
     return kvm_vcpu_ioctl(cs, KVM_SET_ONE_REG, &reg);
 }