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From: Peter Maydell <peter.maydell@linaro.org>
To: qemu-devel@nongnu.org
Subject: [Qemu-devel] [PULL 17/29] target/arm/cpu64: Ensure kvm really supports aarch64=off
Date: Fri, 16 Aug 2019 14:17:07 +0100
Message-ID: <20190816131719.28244-18-peter.maydell@linaro.org> (raw)
In-Reply-To: <20190816131719.28244-1-peter.maydell@linaro.org>

From: Andrew Jones <drjones@redhat.com>

If -cpu <cpu>,aarch64=off is used then KVM must also be used, and it
and the host must support running the vcpu in 32-bit mode. Also, if
-cpu <cpu>,aarch64=on is used, then it doesn't matter if kvm is
enabled or not.

Signed-off-by: Andrew Jones <drjones@redhat.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
 target/arm/kvm_arm.h | 14 ++++++++++++++
 target/arm/cpu64.c   | 12 ++++++------
 target/arm/kvm64.c   |  9 +++++++++
 3 files changed, 29 insertions(+), 6 deletions(-)

diff --git a/target/arm/kvm_arm.h b/target/arm/kvm_arm.h
index 2a07333c615..98af1050a75 100644
--- a/target/arm/kvm_arm.h
+++ b/target/arm/kvm_arm.h
@@ -207,6 +207,15 @@ bool kvm_arm_get_host_cpu_features(ARMHostCPUFeatures *ahcf);
  */
 void kvm_arm_set_cpu_features_from_host(ARMCPU *cpu);
 
+/**
+ * kvm_arm_aarch32_supported:
+ * @cs: CPUState
+ *
+ * Returns: true if the KVM VCPU can enable AArch32 mode
+ * and false otherwise.
+ */
+bool kvm_arm_aarch32_supported(CPUState *cs);
+
 /**
  * kvm_arm_get_max_vm_ipa_size - Returns the number of bits in the
  * IPA address space supported by KVM
@@ -247,6 +256,11 @@ static inline void kvm_arm_set_cpu_features_from_host(ARMCPU *cpu)
     cpu->host_cpu_probe_failed = true;
 }
 
+static inline bool kvm_arm_aarch32_supported(CPUState *cs)
+{
+    return false;
+}
+
 static inline int kvm_arm_get_max_vm_ipa_size(MachineState *ms)
 {
     return -ENOENT;
diff --git a/target/arm/cpu64.c b/target/arm/cpu64.c
index ee55237a9b2..ab63115c776 100644
--- a/target/arm/cpu64.c
+++ b/target/arm/cpu64.c
@@ -426,13 +426,13 @@ static void aarch64_cpu_set_aarch64(Object *obj, bool value, Error **errp)
      * restriction allows us to avoid fixing up functionality that assumes a
      * uniform execution state like do_interrupt.
      */
-    if (!kvm_enabled()) {
-        error_setg(errp, "'aarch64' feature cannot be disabled "
-                         "unless KVM is enabled");
-        return;
-    }
-
     if (value == false) {
+        if (!kvm_enabled() || !kvm_arm_aarch32_supported(CPU(cpu))) {
+            error_setg(errp, "'aarch64' feature cannot be disabled "
+                             "unless KVM is enabled and 32-bit EL1 "
+                             "is supported");
+            return;
+        }
         unset_feature(&cpu->env, ARM_FEATURE_AARCH64);
     } else {
         set_feature(&cpu->env, ARM_FEATURE_AARCH64);
diff --git a/target/arm/kvm64.c b/target/arm/kvm64.c
index 22d19c9aec6..3d91846beb8 100644
--- a/target/arm/kvm64.c
+++ b/target/arm/kvm64.c
@@ -24,7 +24,9 @@
 #include "exec/gdbstub.h"
 #include "sysemu/sysemu.h"
 #include "sysemu/kvm.h"
+#include "sysemu/kvm_int.h"
 #include "kvm_arm.h"
+#include "hw/boards.h"
 #include "internals.h"
 
 static bool have_guest_debug;
@@ -593,6 +595,13 @@ bool kvm_arm_get_host_cpu_features(ARMHostCPUFeatures *ahcf)
     return true;
 }
 
+bool kvm_arm_aarch32_supported(CPUState *cpu)
+{
+    KVMState *s = KVM_STATE(current_machine->accelerator);
+
+    return kvm_check_extension(s, KVM_CAP_ARM_EL1_32BIT);
+}
+
 #define ARM_CPU_ID_MPIDR       3, 0, 0, 0, 5
 
 int kvm_arch_init_vcpu(CPUState *cs)
-- 
2.20.1



  parent reply index

Thread overview: 31+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-08-16 13:16 [Qemu-devel] [PULL 00/29] target-arm queue Peter Maydell
2019-08-16 13:16 ` [Qemu-devel] [PULL 01/29] target/arm: generate a custom MIDR for -cpu max Peter Maydell
2019-08-16 13:16 ` [Qemu-devel] [PULL 02/29] hw/misc/zynq_slcr: use standard register definition Peter Maydell
2019-08-16 13:16 ` [Qemu-devel] [PULL 03/29] Set ENET_BD_BDU in I.MX FEC controller Peter Maydell
2019-08-16 13:16 ` [Qemu-devel] [PULL 04/29] target/arm: Factor out 'generate singlestep exception' function Peter Maydell
2019-08-16 13:16 ` [Qemu-devel] [PULL 05/29] target/arm: Fix routing of singlestep exceptions Peter Maydell
2019-08-16 13:16 ` [Qemu-devel] [PULL 06/29] target/arm: Pass in pc to thumb_insn_is_16bit Peter Maydell
2019-08-16 13:16 ` [Qemu-devel] [PULL 07/29] target/arm: Introduce pc_curr Peter Maydell
2019-08-16 13:16 ` [Qemu-devel] [PULL 08/29] target/arm: Introduce read_pc Peter Maydell
2019-08-16 13:16 ` [Qemu-devel] [PULL 09/29] target/arm: Introduce add_reg_for_lit Peter Maydell
2019-08-16 13:17 ` [Qemu-devel] [PULL 10/29] target/arm: Remove redundant s->pc & ~1 Peter Maydell
2019-08-16 13:17 ` [Qemu-devel] [PULL 11/29] target/arm: Replace s->pc with s->base.pc_next Peter Maydell
2019-08-16 13:17 ` [Qemu-devel] [PULL 12/29] target/arm: Replace offset with pc in gen_exception_insn Peter Maydell
2019-08-16 13:17 ` [Qemu-devel] [PULL 13/29] target/arm: Replace offset with pc in gen_exception_internal_insn Peter Maydell
2019-08-16 13:17 ` [Qemu-devel] [PULL 14/29] target/arm: Remove offset argument to gen_exception_bkpt_insn Peter Maydell
2019-08-16 13:17 ` [Qemu-devel] [PULL 15/29] target/arm: Use unallocated_encoding for aarch32 Peter Maydell
2019-08-16 13:17 ` [Qemu-devel] [PULL 16/29] target/arm: Remove helper_double_saturate Peter Maydell
2019-08-16 13:17 ` Peter Maydell [this message]
2019-08-16 13:17 ` [Qemu-devel] [PULL 18/29] target/arm/cpu: Ensure we can use the pmu with kvm Peter Maydell
2019-08-16 13:17 ` [Qemu-devel] [PULL 19/29] target/arm/helper: zcr: Add build bug next to value range assumption Peter Maydell
2019-08-16 13:17 ` [Qemu-devel] [PULL 20/29] target/arm/cpu: Use div-round-up to determine predicate register array size Peter Maydell
2019-08-16 13:17 ` [Qemu-devel] [PULL 21/29] target/arm/kvm64: Fix error returns Peter Maydell
2019-08-16 13:17 ` [Qemu-devel] [PULL 22/29] target/arm/kvm64: Move the get/put of fpsimd registers out Peter Maydell
2019-08-16 13:17 ` [Qemu-devel] [PULL 23/29] target/arm: Use tcg_gen_extract_i32 for shifter_out_im Peter Maydell
2019-08-16 13:17 ` [Qemu-devel] [PULL 24/29] target/arm: Use tcg_gen_deposit_i32 for PKHBT, PKHTB Peter Maydell
2019-08-16 13:17 ` [Qemu-devel] [PULL 25/29] target/arm: Remove redundant shift tests Peter Maydell
2019-08-16 13:17 ` [Qemu-devel] [PULL 26/29] target/arm: Use ror32 instead of open-coding the operation Peter Maydell
2019-08-16 13:17 ` [Qemu-devel] [PULL 27/29] target/arm: Use tcg_gen_rotri_i32 for gen_swap_half Peter Maydell
2019-08-16 13:17 ` [Qemu-devel] [PULL 28/29] target/arm: Simplify SMMLA, SMMLAR, SMMLS, SMMLSR Peter Maydell
2019-08-16 13:17 ` [Qemu-devel] [PULL 29/29] target/arm: Use tcg_gen_extrh_i64_i32 to extract the high word Peter Maydell
2019-08-16 17:02 ` [Qemu-devel] [PULL 00/29] target-arm queue Peter Maydell

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