LoongArch: KVM: Reload guest CSR registers after sleep

On host, the HW guest CSR registers are lost after suspend and resume
operation. Since last_vcpu of boot CPU still records latest vCPU pointer
so that the guest CSR register skips to reload when boot CPU resumes and
vCPU is scheduled.

Here last_vcpu is cleared so that guest CSR registers will reload from
scheduled vCPU context after suspend and resume.

Cc: stable@vger.kernel.org
Signed-off-by: Bibo Mao <maobibo@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>

diff --git a/arch/loongarch/kvm/main.c b/arch/loongarch/kvm/main.c
index f6d3242b9234a0379e2f7fdfc39251aa840946e4..b6864d6e5ec8d2aedf59a6a69777ad0830f5c1a7 100644 (file)
--- a/arch/loongarch/kvm/main.c
+++ b/arch/loongarch/kvm/main.c
@@ -317,6 +317,13 @@ int kvm_arch_enable_virtualization_cpu(void)
        kvm_debug("GCFG:%lx GSTAT:%lx GINTC:%lx GTLBC:%lx",
                  read_csr_gcfg(), read_csr_gstat(), read_csr_gintc(), read_csr_gtlbc());
 
+       /*
+        * HW Guest CSR registers are lost after CPU suspend and resume.
+        * Clear last_vcpu so that Guest CSR registers forced to reload
+        * from vCPU SW state.
+        */
+       this_cpu_ptr(vmcs)->last_vcpu = NULL;
+
        return 0;
 }