target/arm: Enable TARGET_PAGE_BITS_VARY for AArch64 user-only

Since aarch64 binaries are generally built for multiple page sizes, it is trivial to allow the page size to vary. Signed-off-by: Richard Henderson <richard.henderson@linaro.org> Reviewed-by: Pierrick Bouvier <pierrick.bouvier@linaro.org> Acked-by: Helge Deller <deller@gmx.de> Message-Id: <20240102015808.132373-31-richard.henderson@linaro.org>
qemu · Feb 22, 2024 · 46102f9 · 46102f9
1 parent ea5def1
commit 46102f9
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Showing 2 changed files with 34 additions and 23 deletions.
diff --git a/target/arm/cpu-param.h b/target/arm/cpu-param.h
@@ -19,9 +19,13 @@
 #endif
 
 #ifdef CONFIG_USER_ONLY
-#define TARGET_PAGE_BITS 12
 # ifdef TARGET_AARCH64
 #  define TARGET_TAGGED_ADDRESSES
+/* Allow user-only to vary page size from 4k */
+#  define TARGET_PAGE_BITS_VARY
+#  define TARGET_PAGE_BITS_MIN  12
+# else
+#  define TARGET_PAGE_BITS 12
 # endif
 #else
 /*

diff --git a/target/arm/cpu.c b/target/arm/cpu.c
@@ -1809,7 +1809,6 @@ static void arm_cpu_realizefn(DeviceState *dev, Error **errp)
     ARMCPU *cpu = ARM_CPU(dev);
     ARMCPUClass *acc = ARM_CPU_GET_CLASS(dev);
     CPUARMState *env = &cpu->env;
-    int pagebits;
     Error *local_err = NULL;
 
 #if defined(CONFIG_TCG) && !defined(CONFIG_USER_ONLY)
@@ -2100,28 +2099,36 @@ static void arm_cpu_realizefn(DeviceState *dev, Error **errp)
            !cpu_isar_feature(aa32_vfp_simd, cpu) ||
            !arm_feature(env, ARM_FEATURE_XSCALE));
 
-    if (arm_feature(env, ARM_FEATURE_V7) &&
-        !arm_feature(env, ARM_FEATURE_M) &&
-        !arm_feature(env, ARM_FEATURE_PMSA)) {
-        /* v7VMSA drops support for the old ARMv5 tiny pages, so we
-         * can use 4K pages.
-         */
-        pagebits = 12;
-    } else {
-        /* For CPUs which might have tiny 1K pages, or which have an
-         * MPU and might have small region sizes, stick with 1K pages.
-         */
-        pagebits = 10;
-    }
-    if (!set_preferred_target_page_bits(pagebits)) {
-        /* This can only ever happen for hotplugging a CPU, or if
-         * the board code incorrectly creates a CPU which it has
-         * promised via minimum_page_size that it will not.
-         */
-        error_setg(errp, "This CPU requires a smaller page size than the "
-                   "system is using");
-        return;
+#ifndef CONFIG_USER_ONLY
+    {
+        int pagebits;
+        if (arm_feature(env, ARM_FEATURE_V7) &&
+            !arm_feature(env, ARM_FEATURE_M) &&
+            !arm_feature(env, ARM_FEATURE_PMSA)) {
+            /*
+             * v7VMSA drops support for the old ARMv5 tiny pages,
+             * so we can use 4K pages.
+             */
+            pagebits = 12;
+        } else {
+            /*
+             * For CPUs which might have tiny 1K pages, or which have an
+             * MPU and might have small region sizes, stick with 1K pages.
+             */
+            pagebits = 10;
+        }
+        if (!set_preferred_target_page_bits(pagebits)) {
+            /*
+             * This can only ever happen for hotplugging a CPU, or if
+             * the board code incorrectly creates a CPU which it has
+             * promised via minimum_page_size that it will not.
+             */
+            error_setg(errp, "This CPU requires a smaller page size "
+                       "than the system is using");
+            return;
+        }
     }
+#endif
 
     /* This cpu-id-to-MPIDR affinity is used only for TCG; KVM will override it.
      * We don't support setting cluster ID ([16..23]) (known as Aff2