在 2023/11/16 下午3:19, WANG Xuerui 写道:
On 11/15/23 17:19, Tianrui Zhao wrote:
This patch adds LASX support for LoongArch KVM. The LASX means
LoongArch 256-bits vector instruction.
There will be LASX exception in KVM when guest use the LASX
instruction. KVM will enable LASX and restore the vector
registers for guest then return to guest to continue running.
Signed-off-by: Tianrui Zhao <zhaotianrui@xxxxxxxxxxx>
---
arch/loongarch/include/asm/kvm_host.h | 6 ++++
arch/loongarch/include/asm/kvm_vcpu.h | 10 +++++++
arch/loongarch/kernel/fpu.S | 1 +
arch/loongarch/kvm/exit.c | 18 +++++++++++
arch/loongarch/kvm/switch.S | 16 ++++++++++
arch/loongarch/kvm/trace.h | 4 ++-
arch/loongarch/kvm/vcpu.c | 43 ++++++++++++++++++++++++++-
7 files changed, 96 insertions(+), 2 deletions(-)
diff --git a/arch/loongarch/include/asm/kvm_host.h
b/arch/loongarch/include/asm/kvm_host.h
index 6c65c25169..4c05b5eca0 100644
--- a/arch/loongarch/include/asm/kvm_host.h
+++ b/arch/loongarch/include/asm/kvm_host.h
@@ -95,6 +95,7 @@ enum emulation_result {
#define KVM_LARCH_SWCSR_LATEST (0x1 << 1)
#define KVM_LARCH_HWCSR_USABLE (0x1 << 2)
#define KVM_LARCH_LSX (0x1 << 3)
+#define KVM_LARCH_LASX (0x1 << 4)
struct kvm_vcpu_arch {
/*
@@ -181,6 +182,11 @@ static inline bool kvm_guest_has_lsx(struct
kvm_vcpu_arch *arch)
return arch->cpucfg[2] & CPUCFG2_LSX;
}
+static inline bool kvm_guest_has_lasx(struct kvm_vcpu_arch *arch)
+{
+ return arch->cpucfg[2] & CPUCFG2_LASX;
+}
+
/* Debug: dump vcpu state */
int kvm_arch_vcpu_dump_regs(struct kvm_vcpu *vcpu);
diff --git a/arch/loongarch/include/asm/kvm_vcpu.h
b/arch/loongarch/include/asm/kvm_vcpu.h
index c629771e12..4f87f16018 100644
--- a/arch/loongarch/include/asm/kvm_vcpu.h
+++ b/arch/loongarch/include/asm/kvm_vcpu.h
@@ -67,6 +67,16 @@ static inline void kvm_restore_lsx(struct
loongarch_fpu *fpu) { }
static inline void kvm_restore_lsx_upper(struct loongarch_fpu *fpu)
{ }
#endif
+#ifdef CONFIG_CPU_HAS_LASX
+void kvm_own_lasx(struct kvm_vcpu *vcpu);
+void kvm_save_lasx(struct loongarch_fpu *fpu);
+void kvm_restore_lasx(struct loongarch_fpu *fpu);
+#else
+static inline void kvm_own_lasx(struct kvm_vcpu *vcpu) { }
+static inline void kvm_save_lasx(struct loongarch_fpu *fpu) { }
+static inline void kvm_restore_lasx(struct loongarch_fpu *fpu) { }
+#endif
+
void kvm_acquire_timer(struct kvm_vcpu *vcpu);
void kvm_init_timer(struct kvm_vcpu *vcpu, unsigned long hz);
void kvm_reset_timer(struct kvm_vcpu *vcpu);
diff --git a/arch/loongarch/kernel/fpu.S b/arch/loongarch/kernel/fpu.S
index d53ab10f46..f4524fe866 100644
--- a/arch/loongarch/kernel/fpu.S
+++ b/arch/loongarch/kernel/fpu.S
@@ -384,6 +384,7 @@ SYM_FUNC_START(_restore_lasx_upper)
lasx_restore_all_upper a0 t0 t1
jr ra
SYM_FUNC_END(_restore_lasx_upper)
+EXPORT_SYMBOL(_restore_lasx_upper)
Why the added export? It doesn't seem necessary, given the previous
patch doesn't have a similar export added for _restore_lsx_upper. (Or
if it's truly needed it should probably become EXPORT_SYMBOL_GPL.)
It is needed to be exported, as it is called by kvm_own_lasx. However
the "_restore_lsx_upper" is not used in kvm.
Thanks
Tianrui Zhao
