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-rw-r--r--arch/powerpc/include/asm/cputable.h5
-rw-r--r--arch/powerpc/include/asm/kvm_ppc.h100
-rw-r--r--arch/powerpc/include/asm/reg.h9
3 files changed, 106 insertions, 8 deletions
diff --git a/arch/powerpc/include/asm/cputable.h b/arch/powerpc/include/asm/cputable.h
index a1ebcbc3931f..cf00ff0d121d 100644
--- a/arch/powerpc/include/asm/cputable.h
+++ b/arch/powerpc/include/asm/cputable.h
@@ -209,8 +209,9 @@ static inline void cpu_feature_keys_init(void) { }
#define CPU_FTR_POWER9_DD2_1 LONG_ASM_CONST(0x0000080000000000)
#define CPU_FTR_P9_TM_HV_ASSIST LONG_ASM_CONST(0x0000100000000000)
#define CPU_FTR_P9_TM_XER_SO_BUG LONG_ASM_CONST(0x0000200000000000)
-#define CPU_FTR_P9_TLBIE_BUG LONG_ASM_CONST(0x0000400000000000)
+#define CPU_FTR_P9_TLBIE_STQ_BUG LONG_ASM_CONST(0x0000400000000000)
#define CPU_FTR_P9_TIDR LONG_ASM_CONST(0x0000800000000000)
+#define CPU_FTR_P9_TLBIE_ERAT_BUG LONG_ASM_CONST(0x0001000000000000)
#ifndef __ASSEMBLY__
@@ -457,7 +458,7 @@ static inline void cpu_feature_keys_init(void) { }
CPU_FTR_CFAR | CPU_FTR_HVMODE | CPU_FTR_VMX_COPY | \
CPU_FTR_DBELL | CPU_FTR_HAS_PPR | CPU_FTR_ARCH_207S | \
CPU_FTR_TM_COMP | CPU_FTR_ARCH_300 | CPU_FTR_PKEY | \
- CPU_FTR_P9_TLBIE_BUG | CPU_FTR_P9_TIDR)
+ CPU_FTR_P9_TLBIE_STQ_BUG | CPU_FTR_P9_TLBIE_ERAT_BUG | CPU_FTR_P9_TIDR)
#define CPU_FTRS_POWER9_DD2_0 CPU_FTRS_POWER9
#define CPU_FTRS_POWER9_DD2_1 (CPU_FTRS_POWER9 | CPU_FTR_POWER9_DD2_1)
#define CPU_FTRS_POWER9_DD2_2 (CPU_FTRS_POWER9 | CPU_FTR_POWER9_DD2_1 | \
diff --git a/arch/powerpc/include/asm/kvm_ppc.h b/arch/powerpc/include/asm/kvm_ppc.h
index 8e8514efb124..ee62776e5433 100644
--- a/arch/powerpc/include/asm/kvm_ppc.h
+++ b/arch/powerpc/include/asm/kvm_ppc.h
@@ -452,9 +452,100 @@ static inline u32 kvmppc_get_xics_latch(void)
return xirr;
}
-static inline void kvmppc_set_host_ipi(int cpu, u8 host_ipi)
+/*
+ * To avoid the need to unnecessarily exit fully to the host kernel, an IPI to
+ * a CPU thread that's running/napping inside of a guest is by default regarded
+ * as a request to wake the CPU (if needed) and continue execution within the
+ * guest, potentially to process new state like externally-generated
+ * interrupts or IPIs sent from within the guest itself (e.g. H_PROD/H_IPI).
+ *
+ * To force an exit to the host kernel, kvmppc_set_host_ipi() must be called
+ * prior to issuing the IPI to set the corresponding 'host_ipi' flag in the
+ * target CPU's PACA. To avoid unnecessary exits to the host, this flag should
+ * be immediately cleared via kvmppc_clear_host_ipi() by the IPI handler on
+ * the receiving side prior to processing the IPI work.
+ *
+ * NOTE:
+ *
+ * We currently issue an smp_mb() at the beginning of kvmppc_set_host_ipi().
+ * This is to guard against sequences such as the following:
+ *
+ * CPU
+ * X: smp_muxed_ipi_set_message():
+ * X: smp_mb()
+ * X: message[RESCHEDULE] = 1
+ * X: doorbell_global_ipi(42):
+ * X: kvmppc_set_host_ipi(42)
+ * X: ppc_msgsnd_sync()/smp_mb()
+ * X: ppc_msgsnd() -> 42
+ * 42: doorbell_exception(): // from CPU X
+ * 42: ppc_msgsync()
+ * 105: smp_muxed_ipi_set_message():
+ * 105: smb_mb()
+ * // STORE DEFERRED DUE TO RE-ORDERING
+ * --105: message[CALL_FUNCTION] = 1
+ * | 105: doorbell_global_ipi(42):
+ * | 105: kvmppc_set_host_ipi(42)
+ * | 42: kvmppc_clear_host_ipi(42)
+ * | 42: smp_ipi_demux_relaxed()
+ * | 42: // returns to executing guest
+ * | // RE-ORDERED STORE COMPLETES
+ * ->105: message[CALL_FUNCTION] = 1
+ * 105: ppc_msgsnd_sync()/smp_mb()
+ * 105: ppc_msgsnd() -> 42
+ * 42: local_paca->kvm_hstate.host_ipi == 0 // IPI ignored
+ * 105: // hangs waiting on 42 to process messages/call_single_queue
+ *
+ * We also issue an smp_mb() at the end of kvmppc_clear_host_ipi(). This is
+ * to guard against sequences such as the following (as well as to create
+ * a read-side pairing with the barrier in kvmppc_set_host_ipi()):
+ *
+ * CPU
+ * X: smp_muxed_ipi_set_message():
+ * X: smp_mb()
+ * X: message[RESCHEDULE] = 1
+ * X: doorbell_global_ipi(42):
+ * X: kvmppc_set_host_ipi(42)
+ * X: ppc_msgsnd_sync()/smp_mb()
+ * X: ppc_msgsnd() -> 42
+ * 42: doorbell_exception(): // from CPU X
+ * 42: ppc_msgsync()
+ * // STORE DEFERRED DUE TO RE-ORDERING
+ * -- 42: kvmppc_clear_host_ipi(42)
+ * | 42: smp_ipi_demux_relaxed()
+ * | 105: smp_muxed_ipi_set_message():
+ * | 105: smb_mb()
+ * | 105: message[CALL_FUNCTION] = 1
+ * | 105: doorbell_global_ipi(42):
+ * | 105: kvmppc_set_host_ipi(42)
+ * | // RE-ORDERED STORE COMPLETES
+ * -> 42: kvmppc_clear_host_ipi(42)
+ * 42: // returns to executing guest
+ * 105: ppc_msgsnd_sync()/smp_mb()
+ * 105: ppc_msgsnd() -> 42
+ * 42: local_paca->kvm_hstate.host_ipi == 0 // IPI ignored
+ * 105: // hangs waiting on 42 to process messages/call_single_queue
+ */
+static inline void kvmppc_set_host_ipi(int cpu)
{
- paca_ptrs[cpu]->kvm_hstate.host_ipi = host_ipi;
+ /*
+ * order stores of IPI messages vs. setting of host_ipi flag
+ *
+ * pairs with the barrier in kvmppc_clear_host_ipi()
+ */
+ smp_mb();
+ paca_ptrs[cpu]->kvm_hstate.host_ipi = 1;
+}
+
+static inline void kvmppc_clear_host_ipi(int cpu)
+{
+ paca_ptrs[cpu]->kvm_hstate.host_ipi = 0;
+ /*
+ * order clearing of host_ipi flag vs. processing of IPI messages
+ *
+ * pairs with the barrier in kvmppc_set_host_ipi()
+ */
+ smp_mb();
}
static inline void kvmppc_fast_vcpu_kick(struct kvm_vcpu *vcpu)
@@ -486,7 +577,10 @@ static inline u32 kvmppc_get_xics_latch(void)
return 0;
}
-static inline void kvmppc_set_host_ipi(int cpu, u8 host_ipi)
+static inline void kvmppc_set_host_ipi(int cpu)
+{}
+
+static inline void kvmppc_clear_host_ipi(int cpu)
{}
static inline void kvmppc_fast_vcpu_kick(struct kvm_vcpu *vcpu)
diff --git a/arch/powerpc/include/asm/reg.h b/arch/powerpc/include/asm/reg.h
index ec3714cf0989..b3cbb1136bce 100644
--- a/arch/powerpc/include/asm/reg.h
+++ b/arch/powerpc/include/asm/reg.h
@@ -475,9 +475,10 @@
#define HMER_DEBUG_TRIG (1ul << (63 - 17)) /* Debug trigger */
#define SPRN_HMEER 0x151 /* Hyp maintenance exception enable reg */
#define SPRN_PCR 0x152 /* Processor compatibility register */
-#define PCR_VEC_DIS (1ul << (63-0)) /* Vec. disable (bit NA since POWER8) */
-#define PCR_VSX_DIS (1ul << (63-1)) /* VSX disable (bit NA since POWER8) */
-#define PCR_TM_DIS (1ul << (63-2)) /* Trans. memory disable (POWER8) */
+#define PCR_VEC_DIS (__MASK(63-0)) /* Vec. disable (bit NA since POWER8) */
+#define PCR_VSX_DIS (__MASK(63-1)) /* VSX disable (bit NA since POWER8) */
+#define PCR_TM_DIS (__MASK(63-2)) /* Trans. memory disable (POWER8) */
+#define PCR_HIGH_BITS (PCR_VEC_DIS | PCR_VSX_DIS | PCR_TM_DIS)
/*
* These bits are used in the function kvmppc_set_arch_compat() to specify and
* determine both the compatibility level which we want to emulate and the
@@ -486,6 +487,8 @@
#define PCR_ARCH_207 0x8 /* Architecture 2.07 */
#define PCR_ARCH_206 0x4 /* Architecture 2.06 */
#define PCR_ARCH_205 0x2 /* Architecture 2.05 */
+#define PCR_LOW_BITS (PCR_ARCH_207 | PCR_ARCH_206 | PCR_ARCH_205)
+#define PCR_MASK ~(PCR_HIGH_BITS | PCR_LOW_BITS) /* PCR Reserved Bits */
#define SPRN_HEIR 0x153 /* Hypervisor Emulated Instruction Register */
#define SPRN_TLBINDEXR 0x154 /* P7 TLB control register */
#define SPRN_TLBVPNR 0x155 /* P7 TLB control register */