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[Qemu-devel] [PATCH v5 5/6] target-arm: kvm64 fix save/restore of SPSR r
From: |
Alex Bennée |
Subject: |
[Qemu-devel] [PATCH v5 5/6] target-arm: kvm64 fix save/restore of SPSR regs |
Date: |
Mon, 23 Mar 2015 17:05:43 +0000 |
The current code was negatively indexing the cpu state array and not
synchronizing banked spsr register state with the current mode's spsr
state, causing occasional failures with migration.
Some munging is done to take care of the aarch64 mapping and also to
ensure the most current value of the spsr is updated to the banked
registers (relevant for KVM<->TCG migration).
Signed-off-by: Alex Bennée <address@hidden>
---
v2 (ajb)
- minor tweaks and clarifications
v3
- Use the correct bank index function for setting/getting env->spsr
- only deal with spsrs in elevated exception levels
v4
- try and make commentary clearer
- ensure env->banked_spsr[0] = env->spsr before we sync
v5
- fix banking index now banking fixed
- keep wide spacing on [ ] forms
- claimed authorship
diff --git a/target-arm/kvm64.c b/target-arm/kvm64.c
index 857e970..5270fa7 100644
--- a/target-arm/kvm64.c
+++ b/target-arm/kvm64.c
@@ -139,6 +139,7 @@ int kvm_arch_put_registers(CPUState *cs, int level)
uint64_t val;
int i;
int ret;
+ unsigned int el;
ARMCPU *cpu = ARM_CPU(cs);
CPUARMState *env = &cpu->env;
@@ -205,9 +206,24 @@ int kvm_arch_put_registers(CPUState *cs, int level)
return ret;
}
+ /* Saved Program State Registers
+ *
+ * Before we restore from the banked_spsr[] array we need to
+ * ensure that any modifications to env->spsr are correctly
+ * reflected in the banks.
+ */
+ el = arm_current_el(env);
+ if (el > 0) {
+ i = is_a64(env) ?
+ aarch64_banked_spsr_index(el) :
+ bank_number(env->uncached_cpsr & CPSR_M);
+ env->banked_spsr[i] = env->spsr;
+ }
+
+ /* KVM 0-4 map to QEMU banks 1-5 */
for (i = 0; i < KVM_NR_SPSR; i++) {
reg.id = AARCH64_CORE_REG(spsr[i]);
- reg.addr = (uintptr_t) &env->banked_spsr[i - 1];
+ reg.addr = (uintptr_t) &env->banked_spsr[i + 1];
ret = kvm_vcpu_ioctl(cs, KVM_SET_ONE_REG, ®);
if (ret) {
return ret;
@@ -253,11 +269,13 @@ int kvm_arch_put_registers(CPUState *cs, int level)
return ret;
}
+
int kvm_arch_get_registers(CPUState *cs)
{
struct kvm_one_reg reg;
uint64_t val;
uint32_t fpr;
+ unsigned int el;
int i;
int ret;
@@ -330,15 +348,27 @@ int kvm_arch_get_registers(CPUState *cs)
return ret;
}
+ /* Fetch the SPSR registers
+ *
+ * KVM SPSRs 0-4 map to QEMU banks 1-5
+ */
for (i = 0; i < KVM_NR_SPSR; i++) {
reg.id = AARCH64_CORE_REG(spsr[i]);
- reg.addr = (uintptr_t) &env->banked_spsr[i - 1];
+ reg.addr = (uintptr_t) &env->banked_spsr[i + 1];
ret = kvm_vcpu_ioctl(cs, KVM_GET_ONE_REG, ®);
if (ret) {
return ret;
}
}
+ el = arm_current_el(env);
+ if (el > 0) {
+ i = is_a64(env) ?
+ aarch64_banked_spsr_index(el) :
+ bank_number(env->uncached_cpsr & CPSR_M);
+ env->spsr = env->banked_spsr[i];
+ }
+
/* Advanced SIMD and FP registers
* We map Qn = regs[2n+1]:regs[2n]
*/
--
2.3.2
- [Qemu-devel] [PATCH v5 0/6] QEMU ARM64 Migration Fixes, Alex Bennée, 2015/03/23
- [Qemu-devel] [PATCH v5 6/6] target-arm: cpu.h document why env->spsr exists, Alex Bennée, 2015/03/23
- [Qemu-devel] [PATCH v5 1/6] target-arm: Store SPSR_EL1 state in banked_spsr[1] (SPSR_svc), Alex Bennée, 2015/03/23
- [Qemu-devel] [PATCH v5 4/6] target-arm: kvm64 sync FP register state, Alex Bennée, 2015/03/23
- [Qemu-devel] [PATCH v5 5/6] target-arm: kvm64 fix save/restore of SPSR regs,
Alex Bennée <=
- [Qemu-devel] [PATCH v5 2/6] target-arm: kvm: save/restore mp state, Alex Bennée, 2015/03/23
- [Qemu-devel] [PATCH v5 3/6] hw/intc: arm_gic_kvm.c restore config first, Alex Bennée, 2015/03/23