在 2024/1/22 下午3:12, maobibo 写道:
On 2024/1/22 下午2:09, Song Gao wrote:
The kernel had already support LSX and LASX [1],
but QEMU is disable LSX/LASX for kvm. This patch adds
kvm_check_cpucfg to check CPUCFG2.
[1]:
https://lore.kernel.org/all/cabgobfzhrf7e_7jk4uprmsyxty3eiuuywhc35jqncnl9s-z...@mail.gmail.com/
Signed-off-by: Song Gao <gaos...@loongson.cn>
---
linux-headers/asm-loongarch/kvm.h | 1 +
target/loongarch/kvm/kvm.c | 35 ++++++++++++++++++++++++-------
2 files changed, 29 insertions(+), 7 deletions(-)
diff --git a/linux-headers/asm-loongarch/kvm.h
b/linux-headers/asm-loongarch/kvm.h
index c6ad2ee610..923d0bd382 100644
--- a/linux-headers/asm-loongarch/kvm.h
+++ b/linux-headers/asm-loongarch/kvm.h
@@ -79,6 +79,7 @@ struct kvm_fpu {
#define LOONGARCH_REG_64(TYPE, REG) (TYPE | KVM_REG_SIZE_U64 |
(REG << LOONGARCH_REG_SHIFT))
#define KVM_IOC_CSRID(REG) LOONGARCH_REG_64(KVM_REG_LOONGARCH_CSR,
REG)
#define KVM_IOC_CPUCFG(REG)
LOONGARCH_REG_64(KVM_REG_LOONGARCH_CPUCFG, REG)
+#define KVM_LOONGARCH_VCPU_CPUCFG 0
struct kvm_debug_exit_arch {
};
diff --git a/target/loongarch/kvm/kvm.c b/target/loongarch/kvm/kvm.c
index 84bcdf5f86..41b6947c7b 100644
--- a/target/loongarch/kvm/kvm.c
+++ b/target/loongarch/kvm/kvm.c
@@ -537,6 +537,28 @@ static int kvm_loongarch_get_cpucfg(CPUState *cs)
return ret;
}
+static int kvm_check_cpucfg(int id, CPUState *cs)
+{
+ int ret;
+ uint64_t val;
+ struct kvm_device_attr attr = {
+ .group = KVM_LOONGARCH_VCPU_CPUCFG,
+ .attr = id,
+ .addr = (uint64_t)&val,
+ };
+ LoongArchCPU *cpu = LOONGARCH_CPU(cs);
+ CPULoongArchState *env = &cpu->env;
+
+ ret = kvm_vcpu_ioctl(cs, KVM_HAS_DEVICE_ATTR, &attr);
+
+ if (!ret) {
+ kvm_vcpu_ioctl(cs, KVM_GET_DEVICE_ATTR, &attr);
+ env->cpucfg[id] &= val;
With feature bit represents supported or disabled, it is ok to use
logic of qemu feature bitmap and kvm supported feature bitmap.
However about feature version, there will be problem with "and logic".
Can we use minimal version here?
Yes, we can, I will correct it on v2.
Thanks.
Song Gao
Regards
Bibo Mao
+ }
+
+ return ret;
+}
+
static int kvm_loongarch_put_cpucfg(CPUState *cs)
{
int i, ret = 0;
@@ -545,14 +567,13 @@ static int kvm_loongarch_put_cpucfg(CPUState *cs)
uint64_t val;
for (i = 0; i < 21; i++) {
+ if (i == 2) {
+ ret = kvm_check_cpucfg(i, cs);
+ if (ret) {
+ return ret;
+ }
+ }
val = env->cpucfg[i];
- /* LSX and LASX and LBT are not supported in kvm now */
- if (i == 2) {
- val &= ~(BIT(R_CPUCFG2_LSX_SHIFT) |
BIT(R_CPUCFG2_LASX_SHIFT));
- val &= ~(BIT(R_CPUCFG2_LBT_X86_SHIFT) |
- BIT(R_CPUCFG2_LBT_ARM_SHIFT) |
- BIT(R_CPUCFG2_LBT_MIPS_SHIFT));
- }
ret = kvm_set_one_reg(cs, KVM_IOC_CPUCFG(i), &val);
if (ret < 0) {
trace_kvm_failed_put_cpucfg(strerror(errno));
