diff options
| author | Liu Ping Fan <kernelfans@gmail.com> | 2013-11-19 14:12:48 +0800 |
|---|---|---|
| committer | Alexander Graf <agraf@suse.de> | 2013-11-21 14:56:45 +0100 |
| commit | 27025a602cb9d8b0fa5162b465334ef059a503b6 (patch) | |
| tree | e3d750b573ada011b48143f2ae412ddf57bcbbdf | |
| parent | 8a3caa6d74597c2a083f7c87f866891a0b12540b (diff) | |
powerpc: kvm: optimize "sc 1" as fast return
In some scene, e.g openstack CI, PR guest can trigger "sc 1" frequently,
this patch optimizes the path by directly delivering BOOK3S_INTERRUPT_SYSCALL
to HV guest, so powernv can return to HV guest without heavy exit, i.e,
no need to swap TLB, HTAB,.. etc
Signed-off-by: Liu Ping Fan <pingfank@linux.vnet.ibm.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
| -rw-r--r-- | arch/powerpc/kvm/book3s_hv.c | 10 | ||||
| -rw-r--r-- | arch/powerpc/kvm/book3s_hv_rmhandlers.S | 19 |
2 files changed, 22 insertions, 7 deletions
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c index 072287f1c3b..93203bbe571 100644 --- a/arch/powerpc/kvm/book3s_hv.c +++ b/arch/powerpc/kvm/book3s_hv.c @@ -669,12 +669,10 @@ static int kvmppc_handle_exit_hv(struct kvm_run *run, struct kvm_vcpu *vcpu, /* hcall - punt to userspace */ int i; - if (vcpu->arch.shregs.msr & MSR_PR) { - /* sc 1 from userspace - reflect to guest syscall */ - kvmppc_book3s_queue_irqprio(vcpu, BOOK3S_INTERRUPT_SYSCALL); - r = RESUME_GUEST; - break; - } + /* hypercall with MSR_PR has already been handled in rmode, + * and never reaches here. + */ + run->papr_hcall.nr = kvmppc_get_gpr(vcpu, 3); for (i = 0; i < 9; ++i) run->papr_hcall.args[i] = kvmppc_get_gpr(vcpu, 4 + i); diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S index bc8de75b192..d5ddc2d1074 100644 --- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S +++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S @@ -686,6 +686,13 @@ END_FTR_SECTION_IFSET(CPU_FTR_ARCH_206) 5: mtspr SPRN_SRR0, r6 mtspr SPRN_SRR1, r7 +/* + * Required state: + * R4 = vcpu + * R10: value for HSRR0 + * R11: value for HSRR1 + * R13 = PACA + */ fast_guest_return: li r0,0 stb r0,VCPU_CEDED(r4) /* cancel cede */ @@ -1471,7 +1478,8 @@ kvmppc_hisi: hcall_try_real_mode: ld r3,VCPU_GPR(R3)(r9) andi. r0,r11,MSR_PR - bne guest_exit_cont + /* sc 1 from userspace - reflect to guest syscall */ + bne sc_1_fast_return clrrdi r3,r3,2 cmpldi r3,hcall_real_table_end - hcall_real_table bge guest_exit_cont @@ -1492,6 +1500,15 @@ hcall_try_real_mode: ld r11,VCPU_MSR(r4) b fast_guest_return +sc_1_fast_return: + mtspr SPRN_SRR0,r10 + mtspr SPRN_SRR1,r11 + li r10, BOOK3S_INTERRUPT_SYSCALL + li r11, (MSR_ME << 1) | 1 /* synthesize MSR_SF | MSR_ME */ + rotldi r11, r11, 63 + mr r4,r9 + b fast_guest_return + /* We've attempted a real mode hcall, but it's punted it back * to userspace. We need to restore some clobbered volatiles * before resuming the pass-it-to-qemu path */ |