[PATCH V2 14/14] KVM: MIPS: Enable KVM support for Loongson-3

Huacai Chen
2020-04-24T11:16:51Z

This patch enable KVM support for Loongson-3 by selecting HAVE_KVM, but
only enable KVM/VZ on Loongson-3A R4+ (because VZ of early processors
are incomplete). Besides, Loongson-3 support SMP guests, so we clear the
linked load bit of LLAddr in kvm_vz_vcpu_load() if the guest has more
than one VCPUs.

Signed-off-by: Huacai Chen <chenhc@lemote.com>
Co-developed-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
---
arch/mips/Kconfig | 1 +
arch/mips/kernel/cpu-probe.c | 1 +
arch/mips/kvm/vz.c | 2 +-
3 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index 9f15539..9c4bdac 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -1470,6 +1470,7 @@ config CPU_LOONGSON64
select MIPS_L1_CACHE_SHIFT_6
select GPIOLIB
select SWIOTLB
+ select HAVE_KVM
help
The Loongson GSx64(GS264/GS464/GS464E/GS464V) series of processor
cores implements the MIPS64R2 instruction set with many extensions,
diff --git a/arch/mips/kernel/cpu-probe.c b/arch/mips/kernel/cpu-probe.c
index 5bf0821..c46724e 100644
--- a/arch/mips/kernel/cpu-probe.c
+++ b/arch/mips/kernel/cpu-probe.c
@@ -1958,6 +1958,7 @@ static inline void cpu_probe_loongson(struct cpuinfo_mips *c, unsigned int cpu)
c->writecombine = _CACHE_UNCACHED_ACCELERATED;
c->ases |= (MIPS_ASE_LOONGSON_MMI | MIPS_ASE_LOONGSON_CAM |
MIPS_ASE_LOONGSON_EXT | MIPS_ASE_LOONGSON_EXT2);
+ c->ases &= ~MIPS_ASE_VZ; /* VZ of Loongson-3A2000/3000 is incomplete */
break;
case PRID_IMP_LOONGSON_64G:
c->cputype = CPU_LOONGSON64;
diff --git a/arch/mips/kvm/vz.c b/arch/mips/kvm/vz.c
index 0ea41be..e52955a 100644
--- a/arch/mips/kvm/vz.c
+++ b/arch/mips/kvm/vz.c
@@ -2670,7 +2670,7 @@ static int kvm_vz_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
* prevents a SC on the next VCPU from succeeding by matching a LL on
* the previous VCPU.
*/
- if (cpu_guest_has_rw_llb)
+ if (vcpu->kvm->created_vcpus > 1)
write_gc0_lladdr(0);

return 0;
--
2.7.0