diff options
| -rw-r--r-- | arch/powerpc/include/asm/kvm_host.h | 15 | ||||
| -rw-r--r-- | arch/powerpc/kernel/asm-offsets.c | 2 | ||||
| -rw-r--r-- | arch/powerpc/kvm/book3s_hv.c | 5 | ||||
| -rw-r--r-- | arch/powerpc/kvm/book3s_hv_builtin.c | 10 | ||||
| -rw-r--r-- | arch/powerpc/kvm/book3s_hv_rmhandlers.S | 61 |
5 files changed, 44 insertions, 49 deletions
diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h index 1517faac9b98..d67a83830bd1 100644 --- a/arch/powerpc/include/asm/kvm_host.h +++ b/arch/powerpc/include/asm/kvm_host.h @@ -263,15 +263,15 @@ struct kvm_arch { /* * Struct for a virtual core. - * Note: entry_exit_count combines an entry count in the bottom 8 bits - * and an exit count in the next 8 bits. This is so that we can - * atomically increment the entry count iff the exit count is 0 - * without taking the lock. + * Note: entry_exit_map combines a bitmap of threads that have entered + * in the bottom 8 bits and a bitmap of threads that have exited in the + * next 8 bits. This is so that we can atomically set the entry bit + * iff the exit map is 0 without taking a lock. */ struct kvmppc_vcore { int n_runnable; int num_threads; - int entry_exit_count; + int entry_exit_map; int napping_threads; int first_vcpuid; u16 pcpu; @@ -296,8 +296,9 @@ struct kvmppc_vcore { ulong conferring_threads; }; -#define VCORE_ENTRY_COUNT(vc) ((vc)->entry_exit_count & 0xff) -#define VCORE_EXIT_COUNT(vc) ((vc)->entry_exit_count >> 8) +#define VCORE_ENTRY_MAP(vc) ((vc)->entry_exit_map & 0xff) +#define VCORE_EXIT_MAP(vc) ((vc)->entry_exit_map >> 8) +#define VCORE_IS_EXITING(vc) (VCORE_EXIT_MAP(vc) != 0) /* Values for vcore_state */ #define VCORE_INACTIVE 0 diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c index 8aa824681d76..0d07efbe3fa7 100644 --- a/arch/powerpc/kernel/asm-offsets.c +++ b/arch/powerpc/kernel/asm-offsets.c @@ -562,7 +562,7 @@ int main(void) DEFINE(VCPU_ACOP, offsetof(struct kvm_vcpu, arch.acop)); DEFINE(VCPU_WORT, offsetof(struct kvm_vcpu, arch.wort)); DEFINE(VCPU_SHADOW_SRR1, offsetof(struct kvm_vcpu, arch.shadow_srr1)); - DEFINE(VCORE_ENTRY_EXIT, offsetof(struct kvmppc_vcore, entry_exit_count)); + DEFINE(VCORE_ENTRY_EXIT, offsetof(struct kvmppc_vcore, entry_exit_map)); DEFINE(VCORE_IN_GUEST, offsetof(struct kvmppc_vcore, in_guest)); DEFINE(VCORE_NAPPING_THREADS, offsetof(struct kvmppc_vcore, napping_threads)); DEFINE(VCORE_KVM, offsetof(struct kvmppc_vcore, kvm)); diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c index 7c1335dca4a5..ea1600ff52b2 100644 --- a/arch/powerpc/kvm/book3s_hv.c +++ b/arch/powerpc/kvm/book3s_hv.c @@ -1952,7 +1952,7 @@ static void kvmppc_run_core(struct kvmppc_vcore *vc) /* * Initialize *vc. */ - vc->entry_exit_count = 0; + vc->entry_exit_map = 0; vc->preempt_tb = TB_NIL; vc->in_guest = 0; vc->napping_threads = 0; @@ -2119,8 +2119,7 @@ static int kvmppc_run_vcpu(struct kvm_run *kvm_run, struct kvm_vcpu *vcpu) * this thread straight away and have it join in. */ if (!signal_pending(current)) { - if (vc->vcore_state == VCORE_RUNNING && - VCORE_EXIT_COUNT(vc) == 0) { + if (vc->vcore_state == VCORE_RUNNING && !VCORE_IS_EXITING(vc)) { kvmppc_create_dtl_entry(vcpu, vc); kvmppc_start_thread(vcpu); trace_kvm_guest_enter(vcpu); diff --git a/arch/powerpc/kvm/book3s_hv_builtin.c b/arch/powerpc/kvm/book3s_hv_builtin.c index 1954a1c4b1f9..275425142bb7 100644 --- a/arch/powerpc/kvm/book3s_hv_builtin.c +++ b/arch/powerpc/kvm/book3s_hv_builtin.c @@ -115,11 +115,11 @@ long int kvmppc_rm_h_confer(struct kvm_vcpu *vcpu, int target, int rv = H_SUCCESS; /* => don't yield */ set_bit(vcpu->arch.ptid, &vc->conferring_threads); - while ((get_tb() < stop) && (VCORE_EXIT_COUNT(vc) == 0)) { - threads_running = VCORE_ENTRY_COUNT(vc); - threads_ceded = hweight32(vc->napping_threads); - threads_conferring = hweight32(vc->conferring_threads); - if (threads_ceded + threads_conferring >= threads_running) { + while ((get_tb() < stop) && !VCORE_IS_EXITING(vc)) { + threads_running = VCORE_ENTRY_MAP(vc); + threads_ceded = vc->napping_threads; + threads_conferring = vc->conferring_threads; + if ((threads_ceded | threads_conferring) == threads_running) { rv = H_TOO_HARD; /* => do yield */ break; } diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S index 16719af88bcc..245f5c972030 100644 --- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S +++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S @@ -185,7 +185,7 @@ kvmppc_primary_no_guest: or r3, r3, r0 stwcx. r3, 0, r6 bne 1b - /* order napping_threads update vs testing entry_exit_count */ + /* order napping_threads update vs testing entry_exit_map */ isync li r12, 0 lwz r7, VCORE_ENTRY_EXIT(r5) @@ -406,19 +406,21 @@ kvmppc_hv_entry: * We don't have to lock against concurrent tlbies, * but we do have to coordinate across hardware threads. */ - /* Increment entry count iff exit count is zero. */ - ld r5,HSTATE_KVM_VCORE(r13) - addi r9,r5,VCORE_ENTRY_EXIT -21: lwarx r3,0,r9 - cmpwi r3,0x100 /* any threads starting to exit? */ + /* Set bit in entry map iff exit map is zero. */ + ld r5, HSTATE_KVM_VCORE(r13) + li r7, 1 + lbz r6, HSTATE_PTID(r13) + sld r7, r7, r6 + addi r9, r5, VCORE_ENTRY_EXIT +21: lwarx r3, 0, r9 + cmpwi r3, 0x100 /* any threads starting to exit? */ bge secondary_too_late /* if so we're too late to the party */ - addi r3,r3,1 - stwcx. r3,0,r9 + or r3, r3, r7 + stwcx. r3, 0, r9 bne 21b /* Primary thread switches to guest partition. */ ld r9,VCORE_KVM(r5) /* pointer to struct kvm */ - lbz r6,HSTATE_PTID(r13) cmpwi r6,0 bne 20f ld r6,KVM_SDR1(r9) @@ -1477,13 +1479,16 @@ kvmhv_do_exit: /* r12 = trap, r13 = paca */ * We don't have to lock against tlbies but we do * have to coordinate the hardware threads. */ - /* Increment the threads-exiting-guest count in the 0xff00 - bits of vcore->entry_exit_count */ - ld r5,HSTATE_KVM_VCORE(r13) - addi r6,r5,VCORE_ENTRY_EXIT -41: lwarx r3,0,r6 - addi r0,r3,0x100 - stwcx. r0,0,r6 + /* Set our bit in the threads-exiting-guest map in the 0xff00 + bits of vcore->entry_exit_map */ + ld r5, HSTATE_KVM_VCORE(r13) + lbz r4, HSTATE_PTID(r13) + li r7, 0x100 + sld r7, r7, r4 + addi r6, r5, VCORE_ENTRY_EXIT +41: lwarx r3, 0, r6 + or r0, r3, r7 + stwcx. r0, 0, r6 bne 41b isync /* order stwcx. vs. reading napping_threads */ @@ -1492,9 +1497,9 @@ kvmhv_do_exit: /* r12 = trap, r13 = paca */ * up to the kernel or qemu; we can't handle it in real mode. * Thus we have to do a partition switch, so we have to * collect the other threads, if we are the first thread - * to take an interrupt. To do this, we set the HDEC to 0, - * which causes an HDEC interrupt in all threads within 2ns - * because the HDEC register is shared between all 4 threads. + * to take an interrupt. To do this, we send a message or + * IPI to all the threads that have their bit set in the entry + * map in vcore->entry_exit_map (other than ourselves). * However, we don't need to bother if this is an HDEC * interrupt, since the other threads will already be on their * way here in that case. @@ -1503,17 +1508,8 @@ kvmhv_do_exit: /* r12 = trap, r13 = paca */ bge 43f cmpwi r12,BOOK3S_INTERRUPT_HV_DECREMENTER beq 43f - li r0,0 - mtspr SPRN_HDEC,r0 - /* - * Send an IPI to any napping threads, since an HDEC interrupt - * doesn't wake CPUs up from nap. - */ - lwz r3,VCORE_NAPPING_THREADS(r5) - lbz r4,HSTATE_PTID(r13) - li r0,1 - sld r0,r0,r4 + srwi r0,r7,8 andc. r3,r3,r0 /* no sense IPI'ing ourselves */ beq 43f /* Order entry/exit update vs. IPIs */ @@ -2091,12 +2087,11 @@ _GLOBAL(kvmppc_h_cede) /* r3 = vcpu pointer, r11 = msr, r13 = paca */ addi r6,r5,VCORE_NAPPING_THREADS 31: lwarx r4,0,r6 or r4,r4,r0 - PPC_POPCNTW(R7,R4) - cmpw r7,r8 - bge kvm_cede_exit + cmpw r4,r8 + beq kvm_cede_exit stwcx. r4,0,r6 bne 31b - /* order napping_threads update vs testing entry_exit_count */ + /* order napping_threads update vs testing entry_exit_map */ isync li r0,NAPPING_CEDE stb r0,HSTATE_NAPPING(r13) |