Merge remote-tracking branch 'remotes/pmaydell/tags/pull-target-arm-20190507' into staging

target-arm queue:
 * Stop using variable length array in dc_zva
 * Implement M-profile XPSR GE bits
 * Don't enable ARMV7M_EXCP_DEBUG from reset
 * armv7m_nvic: NS BFAR and BFSR are RAZ/WI if BFHFNMINS == 0
 * armv7m_nvic: Check subpriority in nvic_recompute_state_secure()
 * fix various minor issues to allow building for Windows-on-ARM64
 * aspeed: Set SDRAM size
 * Allow system registers for KVM guests to be changed by QEMU code
 * raspi: Diagnose requests for too much RAM
 * virt: Support firmware configuration with -blockdev

# gpg: Signature made Tue 07 May 2019 12:59:30 BST
# gpg:                using RSA key E1A5C593CD419DE28E8315CF3C2525ED14360CDE
# gpg:                issuer "peter.maydell@linaro.org"
# gpg: Good signature from "Peter Maydell <peter.maydell@linaro.org>" [ultimate]
# gpg:                 aka "Peter Maydell <pmaydell@gmail.com>" [ultimate]
# gpg:                 aka "Peter Maydell <pmaydell@chiark.greenend.org.uk>" [ultimate]
# Primary key fingerprint: E1A5 C593 CD41 9DE2 8E83  15CF 3C25 25ED 1436 0CDE

* remotes/pmaydell/tags/pull-target-arm-20190507:
  target/arm: Stop using variable length array in dc_zva
  target/arm: Implement XPSR GE bits
  hw/intc/armv7m_nvic: Don't enable ARMV7M_EXCP_DEBUG from reset
  hw/intc/armv7m_nvic: NS BFAR and BFSR are RAZ/WI if BFHFNMINS == 0
  hw/arm/armv7m_nvic: Check subpriority in nvic_recompute_state_secure()
  osdep: Fix mingw compilation regarding stdio formats
  util/cacheinfo: Use uint64_t on LLP64 model to satisfy Windows ARM64
  qga: Fix mingw compilation warnings on enum conversion
  QEMU_PACKED: Remove gcc_struct attribute in Windows non x86 targets
  arm: aspeed: Set SDRAM size
  arm: Allow system registers for KVM guests to be changed by QEMU code
  hw/arm/raspi: Diagnose requests for too much RAM
  hw/arm/virt: Support firmware configuration with -blockdev
  pflash_cfi01: New pflash_cfi01_legacy_drive()
  pc: Rearrange pc_system_firmware_init()'s legacy -drive loop

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

6 files changed, 66 insertions, 26 deletions

diff --git a/target/arm/cpu.h b/target/arm/cpu.h
index 22bc6e0..733b840 100644
--- a/target/arm/cpu.h
+++ b/target/arm/cpu.h
@@ -1285,6 +1285,7 @@ static inline uint32_t xpsr_read(CPUARMState *env)
         | (env->CF << 29) | ((env->VF & 0x80000000) >> 3) | (env->QF << 27)
         | (env->thumb << 24) | ((env->condexec_bits & 3) << 25)
         | ((env->condexec_bits & 0xfc) << 8)
+        | (env->GE << 16)
         | env->v7m.exception;
 }
 
@@ -1300,6 +1301,9 @@ static inline void xpsr_write(CPUARMState *env, uint32_t val, uint32_t mask)
     if (mask & XPSR_Q) {
         env->QF = ((val & XPSR_Q) != 0);
     }
+    if (mask & XPSR_GE) {
+        env->GE = (val & XPSR_GE) >> 16;
+    }
     if (mask & XPSR_T) {
         env->thumb = ((val & XPSR_T) != 0);
     }
@@ -2610,18 +2614,25 @@ bool write_list_to_cpustate(ARMCPU *cpu);
 /**
  * write_cpustate_to_list:
  * @cpu: ARMCPU
+ * @kvm_sync: true if this is for syncing back to KVM
  *
  * For each register listed in the ARMCPU cpreg_indexes list, write
  * its value from the ARMCPUState structure into the cpreg_values list.
  * This is used to copy info from TCG's working data structures into
  * KVM or for outbound migration.
  *
+ * @kvm_sync is true if we are doing this in order to sync the
+ * register state back to KVM. In this case we will only update
+ * values in the list if the previous list->cpustate sync actually
+ * successfully wrote the CPU state. Otherwise we will keep the value
+ * that is in the list.
+ *
  * Returns: true if all register values were read correctly,
  * false if some register was unknown or could not be read.
  * Note that we do not stop early on failure -- we will attempt
  * reading all registers in the list.
  */
-bool write_cpustate_to_list(ARMCPU *cpu);
+bool write_cpustate_to_list(ARMCPU *cpu, bool kvm_sync);
 
 #define ARM_CPUID_TI915T      0x54029152
 #define ARM_CPUID_TI925T      0x54029252
diff --git a/target/arm/helper.c b/target/arm/helper.c
index 81a92ab..1e6eb0d 100644
--- a/target/arm/helper.c
+++ b/target/arm/helper.c
@@ -1,4 +1,5 @@
 #include "qemu/osdep.h"
+#include "qemu/units.h"
 #include "target/arm/idau.h"
 #include "trace.h"
 #include "cpu.h"
@@ -266,7 +267,7 @@ static bool raw_accessors_invalid(const ARMCPRegInfo *ri)
     return true;
 }
 
-bool write_cpustate_to_list(ARMCPU *cpu)
+bool write_cpustate_to_list(ARMCPU *cpu, bool kvm_sync)
 {
     /* Write the coprocessor state from cpu->env to the (index,value) list. */
     int i;
@@ -275,6 +276,7 @@ bool write_cpustate_to_list(ARMCPU *cpu)
     for (i = 0; i < cpu->cpreg_array_len; i++) {
         uint32_t regidx = kvm_to_cpreg_id(cpu->cpreg_indexes[i]);
         const ARMCPRegInfo *ri;
+        uint64_t newval;
 
         ri = get_arm_cp_reginfo(cpu->cp_regs, regidx);
         if (!ri) {
@@ -284,7 +286,29 @@ bool write_cpustate_to_list(ARMCPU *cpu)
         if (ri->type & ARM_CP_NO_RAW) {
             continue;
         }
-        cpu->cpreg_values[i] = read_raw_cp_reg(&cpu->env, ri);
+
+        newval = read_raw_cp_reg(&cpu->env, ri);
+        if (kvm_sync) {
+            /*
+             * Only sync if the previous list->cpustate sync succeeded.
+             * Rather than tracking the success/failure state for every
+             * item in the list, we just recheck "does the raw write we must
+             * have made in write_list_to_cpustate() read back OK" here.
+             */
+            uint64_t oldval = cpu->cpreg_values[i];
+
+            if (oldval == newval) {
+                continue;
+            }
+
+            write_raw_cp_reg(&cpu->env, ri, oldval);
+            if (read_raw_cp_reg(&cpu->env, ri) != oldval) {
+                continue;
+            }
+
+            write_raw_cp_reg(&cpu->env, ri, newval);
+        }
+        cpu->cpreg_values[i] = newval;
     }
     return ok;
 }
@@ -8704,7 +8728,7 @@ static void do_v7m_exception_exit(ARMCPU *cpu)
 {
     CPUARMState *env = &cpu->env;
     uint32_t excret;
-    uint32_t xpsr;
+    uint32_t xpsr, xpsr_mask;
     bool ufault = false;
     bool sfault = false;
     bool return_to_sp_process;
@@ -9156,8 +9180,13 @@ static void do_v7m_exception_exit(ARMCPU *cpu)
         }
         *frame_sp_p = frameptr;
     }
+
+    xpsr_mask = ~(XPSR_SPREALIGN | XPSR_SFPA);
+    if (!arm_feature(env, ARM_FEATURE_THUMB_DSP)) {
+        xpsr_mask &= ~XPSR_GE;
+    }
     /* This xpsr_write() will invalidate frame_sp_p as it may switch stack */
-    xpsr_write(env, xpsr, ~(XPSR_SPREALIGN | XPSR_SFPA));
+    xpsr_write(env, xpsr, xpsr_mask);
 
     if (env->v7m.secure) {
         bool sfpa = xpsr & XPSR_SFPA;
@@ -12642,6 +12671,9 @@ uint32_t HELPER(v7m_mrs)(CPUARMState *env, uint32_t reg)
         }
         if (!(reg & 4)) {
             mask |= XPSR_NZCV | XPSR_Q; /* APSR */
+            if (arm_feature(env, ARM_FEATURE_THUMB_DSP)) {
+                mask |= XPSR_GE;
+            }
         }
         /* EPSR reads as zero */
         return xpsr_read(env) & mask;
@@ -13099,14 +13131,17 @@ void HELPER(dc_zva)(CPUARMState *env, uint64_t vaddr_in)
          * We know that in fact for any v8 CPU the page size is at least 4K
          * and the block size must be 2K or less, but TARGET_PAGE_SIZE is only
          * 1K as an artefact of legacy v5 subpage support being present in the
-         * same QEMU executable.
+         * same QEMU executable. So in practice the hostaddr[] array has
+         * two entries, given the current setting of TARGET_PAGE_BITS_MIN.
          */
         int maxidx = DIV_ROUND_UP(blocklen, TARGET_PAGE_SIZE);
-        void *hostaddr[maxidx];
+        void *hostaddr[DIV_ROUND_UP(2 * KiB, 1 << TARGET_PAGE_BITS_MIN)];
         int try, i;
         unsigned mmu_idx = cpu_mmu_index(env, false);
         TCGMemOpIdx oi = make_memop_idx(MO_UB, mmu_idx);
 
+        assert(maxidx <= ARRAY_SIZE(hostaddr));
+
         for (try = 0; try < 2; try++) {
 
             for (i = 0; i < maxidx; i++) {
diff --git a/target/arm/kvm.c b/target/arm/kvm.c
index 79a79f0..5995634 100644
--- a/target/arm/kvm.c
+++ b/target/arm/kvm.c
@@ -497,6 +497,14 @@ void kvm_arm_reset_vcpu(ARMCPU *cpu)
         fprintf(stderr, "write_kvmstate_to_list failed\n");
         abort();
     }
+    /*
+     * Sync the reset values also into the CPUState. This is necessary
+     * because the next thing we do will be a kvm_arch_put_registers()
+     * which will update the list values from the CPUState before copying
+     * the list values back to KVM. It's OK to ignore failure returns here
+     * for the same reason we do so in kvm_arch_get_registers().
+     */
+    write_list_to_cpustate(cpu);
 }
 
 /*
diff --git a/target/arm/kvm32.c b/target/arm/kvm32.c
index 5032798..327375f 100644
--- a/target/arm/kvm32.c
+++ b/target/arm/kvm32.c
@@ -384,24 +384,8 @@ int kvm_arch_put_registers(CPUState *cs, int level)
         return ret;
     }
 
-    /* Note that we do not call write_cpustate_to_list()
-     * here, so we are only writing the tuple list back to
-     * KVM. This is safe because nothing can change the
-     * CPUARMState cp15 fields (in particular gdb accesses cannot)
-     * and so there are no changes to sync. In fact syncing would
-     * be wrong at this point: for a constant register where TCG and
-     * KVM disagree about its value, the preceding write_list_to_cpustate()
-     * would not have had any effect on the CPUARMState value (since the
-     * register is read-only), and a write_cpustate_to_list() here would
-     * then try to write the TCG value back into KVM -- this would either
-     * fail or incorrectly change the value the guest sees.
-     *
-     * If we ever want to allow the user to modify cp15 registers via
-     * the gdb stub, we would need to be more clever here (for instance
-     * tracking the set of registers kvm_arch_get_registers() successfully
-     * managed to update the CPUARMState with, and only allowing those
-     * to be written back up into the kernel).
-     */
+    write_cpustate_to_list(cpu, true);
+
     if (!write_list_to_kvmstate(cpu, level)) {
         return EINVAL;
     }
diff --git a/target/arm/kvm64.c b/target/arm/kvm64.c
index 089af9c..e3ba149 100644
--- a/target/arm/kvm64.c
+++ b/target/arm/kvm64.c
@@ -838,6 +838,8 @@ int kvm_arch_put_registers(CPUState *cs, int level)
         return ret;
     }
 
+    write_cpustate_to_list(cpu, true);
+
     if (!write_list_to_kvmstate(cpu, level)) {
         return EINVAL;
     }
diff --git a/target/arm/machine.c b/target/arm/machine.c
index 09567d4..96d032f 100644
--- a/target/arm/machine.c
+++ b/target/arm/machine.c
@@ -646,7 +646,7 @@ static int cpu_pre_save(void *opaque)
             abort();
         }
     } else {
-        if (!write_cpustate_to_list(cpu)) {
+        if (!write_cpustate_to_list(cpu, false)) {
             /* This should never fail. */
             abort();
         }