--- /dev/null
+/*
+ * Hypervisor Maintenance Interrupt header file.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.
+ *
+ * Copyright 2015 IBM Corporation
+ * Author: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
+ */
+
+#ifndef __ASM_PPC64_HMI_H__
+#define __ASM_PPC64_HMI_H__
+
+#ifdef CONFIG_PPC_BOOK3S_64
+
+#define CORE_TB_RESYNC_REQ_BIT 63
+#define MAX_SUBCORE_PER_CORE 4
+
+/*
+ * sibling_subcore_state structure is used to co-ordinate all threads
+ * during HMI to avoid TB corruption. This structure is allocated once
+ * per each core and shared by all threads on that core.
+ */
+struct sibling_subcore_state {
+ unsigned long flags;
+ u8 in_guest[MAX_SUBCORE_PER_CORE];
+};
+
+extern void wait_for_subcore_guest_exit(void);
+extern void wait_for_tb_resync(void);
+#else
+static inline void wait_for_subcore_guest_exit(void) { }
+static inline void wait_for_tb_resync(void) { }
+#endif
+#endif /* __ASM_PPC64_HMI_H__ */
#ifdef CONFIG_KVM_BOOK3S_64_HANDLER
#include <asm/kvm_book3s_asm.h>
#endif
+#include <asm/hmi.h>
register struct paca_struct *local_paca asm("r13");
*/
u16 in_mce;
u8 hmi_event_available; /* HMI event is available */
+ /*
+ * Bitmap for sibling subcore status. See kvm/book3s_hv_ras.c for
+ * more details
+ */
+ struct sibling_subcore_state *sibling_subcore_state;
#endif
/* Stuff for accurate time accounting */
obj-$(CONFIG_HAVE_HW_BREAKPOINT) += hw_breakpoint.o
obj-$(CONFIG_PPC_BOOK3S_64) += cpu_setup_ppc970.o cpu_setup_pa6t.o
obj-$(CONFIG_PPC_BOOK3S_64) += cpu_setup_power.o
-obj-$(CONFIG_PPC_BOOK3S_64) += mce.o mce_power.o
+obj-$(CONFIG_PPC_BOOK3S_64) += mce.o mce_power.o hmi.o
obj64-$(CONFIG_RELOCATABLE) += reloc_64.o
obj-$(CONFIG_PPC_BOOK3E_64) += exceptions-64e.o idle_book3e.o
obj-$(CONFIG_PPC64) += vdso64/
BEGIN_FTR_SECTION
cmpwi r3,0xe80
beq h_doorbell_common
+ cmpwi r3,0xe60
+ beq hmi_exception_common
FTR_SECTION_ELSE
cmpwi r3,0xa00
beq doorbell_super_common
.globl hmi_exception_early
hmi_exception_early:
- EXCEPTION_PROLOG_1(PACA_EXGEN, NOTEST, 0xe60)
+ EXCEPTION_PROLOG_1(PACA_EXGEN, KVMTEST, 0xe62)
mr r10,r1 /* Save r1 */
ld r1,PACAEMERGSP(r13) /* Use emergency stack */
subi r1,r1,INT_FRAME_SIZE /* alloc stack frame */
--- /dev/null
+/*
+ * Hypervisor Maintenance Interrupt (HMI) handling.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.
+ *
+ * Copyright 2015 IBM Corporation
+ * Author: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
+ */
+
+#undef DEBUG
+
+#include <linux/types.h>
+#include <linux/compiler.h>
+#include <asm/paca.h>
+#include <asm/hmi.h>
+
+void wait_for_subcore_guest_exit(void)
+{
+ int i;
+
+ /*
+ * NULL bitmap pointer indicates that KVM module hasn't
+ * been loaded yet and hence no guests are running.
+ * If no KVM is in use, no need to co-ordinate among threads
+ * as all of them will always be in host and no one is going
+ * to modify TB other than the opal hmi handler.
+ * Hence, just return from here.
+ */
+ if (!local_paca->sibling_subcore_state)
+ return;
+
+ for (i = 0; i < MAX_SUBCORE_PER_CORE; i++)
+ while (local_paca->sibling_subcore_state->in_guest[i])
+ cpu_relax();
+}
+
+void wait_for_tb_resync(void)
+{
+ if (!local_paca->sibling_subcore_state)
+ return;
+
+ while (test_bit(CORE_TB_RESYNC_REQ_BIT,
+ &local_paca->sibling_subcore_state->flags))
+ cpu_relax();
+}
ld r2,PACATOC(r13); \
ld r1,PACAR1(r13); \
std r3,ORIG_GPR3(r1); /* Save original r3 */ \
- li r0,OPAL_HANDLE_HMI; /* Pass opal token argument*/ \
- bl opal_call_realmode; \
+ li r3,0; /* NULL argument */ \
+ bl hmi_exception_realmode; \
+ nop; \
ld r3,ORIG_GPR3(r1); /* Restore original r3 */ \
20: nop;
#include <asm/switch_to.h>
#include <asm/tm.h>
#include <asm/debug.h>
+#include <asm/hmi.h>
#include <sysdev/fsl_pci.h>
#if defined(CONFIG_DEBUGGER) || defined(CONFIG_KEXEC)
{
__this_cpu_inc(irq_stat.hmi_exceptions);
+ wait_for_subcore_guest_exit();
+
if (ppc_md.hmi_exception_early)
ppc_md.hmi_exception_early(regs);
+ wait_for_tb_resync();
+
return 0;
}
#include <asm/switch_to.h>
#include <asm/smp.h>
#include <asm/dbell.h>
+#include <asm/hmi.h>
#include <linux/gfp.h>
#include <linux/vmalloc.h>
#include <linux/highmem.h>
.hcall_implemented = kvmppc_hcall_impl_hv,
};
+static int kvm_init_subcore_bitmap(void)
+{
+ int i, j;
+ int nr_cores = cpu_nr_cores();
+ struct sibling_subcore_state *sibling_subcore_state;
+
+ for (i = 0; i < nr_cores; i++) {
+ int first_cpu = i * threads_per_core;
+ int node = cpu_to_node(first_cpu);
+
+ /* Ignore if it is already allocated. */
+ if (paca[first_cpu].sibling_subcore_state)
+ continue;
+
+ sibling_subcore_state =
+ kmalloc_node(sizeof(struct sibling_subcore_state),
+ GFP_KERNEL, node);
+ if (!sibling_subcore_state)
+ return -ENOMEM;
+
+ memset(sibling_subcore_state, 0,
+ sizeof(struct sibling_subcore_state));
+
+ for (j = 0; j < threads_per_core; j++) {
+ int cpu = first_cpu + j;
+
+ paca[cpu].sibling_subcore_state = sibling_subcore_state;
+ }
+ }
+ return 0;
+}
+
static int kvmppc_book3s_init_hv(void)
{
int r;
if (r < 0)
return -ENODEV;
+ r = kvm_init_subcore_bitmap();
+ if (r)
+ return r;
+
kvm_ops_hv.owner = THIS_MODULE;
kvmppc_hv_ops = &kvm_ops_hv;
#include <linux/kernel.h>
#include <asm/opal.h>
#include <asm/mce.h>
+#include <asm/machdep.h>
+#include <asm/cputhreads.h>
+#include <asm/hmi.h>
/* SRR1 bits for machine check on POWER7 */
#define SRR1_MC_LDSTERR (1ul << (63-42))
{
return kvmppc_realmode_mc_power7(vcpu);
}
+
+/* Check if dynamic split is in force and return subcore size accordingly. */
+static inline int kvmppc_cur_subcore_size(void)
+{
+ if (local_paca->kvm_hstate.kvm_split_mode)
+ return local_paca->kvm_hstate.kvm_split_mode->subcore_size;
+
+ return threads_per_subcore;
+}
+
+void kvmppc_subcore_enter_guest(void)
+{
+ int thread_id, subcore_id;
+
+ thread_id = cpu_thread_in_core(local_paca->paca_index);
+ subcore_id = thread_id / kvmppc_cur_subcore_size();
+
+ local_paca->sibling_subcore_state->in_guest[subcore_id] = 1;
+}
+
+void kvmppc_subcore_exit_guest(void)
+{
+ int thread_id, subcore_id;
+
+ thread_id = cpu_thread_in_core(local_paca->paca_index);
+ subcore_id = thread_id / kvmppc_cur_subcore_size();
+
+ local_paca->sibling_subcore_state->in_guest[subcore_id] = 0;
+}
+
+static bool kvmppc_tb_resync_required(void)
+{
+ if (test_and_set_bit(CORE_TB_RESYNC_REQ_BIT,
+ &local_paca->sibling_subcore_state->flags))
+ return false;
+
+ return true;
+}
+
+static void kvmppc_tb_resync_done(void)
+{
+ clear_bit(CORE_TB_RESYNC_REQ_BIT,
+ &local_paca->sibling_subcore_state->flags);
+}
+
+/*
+ * kvmppc_realmode_hmi_handler() is called only by primary thread during
+ * guest exit path.
+ *
+ * There are multiple reasons why HMI could occur, one of them is
+ * Timebase (TB) error. If this HMI is due to TB error, then TB would
+ * have been in stopped state. The opal hmi handler Will fix it and
+ * restore the TB value with host timebase value. For HMI caused due
+ * to non-TB errors, opal hmi handler will not touch/restore TB register
+ * and hence there won't be any change in TB value.
+ *
+ * Since we are not sure about the cause of this HMI, we can't be sure
+ * about the content of TB register whether it holds guest or host timebase
+ * value. Hence the idea is to resync the TB on every HMI, so that we
+ * know about the exact state of the TB value. Resync TB call will
+ * restore TB to host timebase.
+ *
+ * Things to consider:
+ * - On TB error, HMI interrupt is reported on all the threads of the core
+ * that has encountered TB error irrespective of split-core mode.
+ * - The very first thread on the core that get chance to fix TB error
+ * would rsync the TB with local chipTOD value.
+ * - The resync TB is a core level action i.e. it will sync all the TBs
+ * in that core independent of split-core mode. This means if we trigger
+ * TB sync from a thread from one subcore, it would affect TB values of
+ * sibling subcores of the same core.
+ *
+ * All threads need to co-ordinate before making opal hmi handler.
+ * All threads will use sibling_subcore_state->in_guest[] (shared by all
+ * threads in the core) in paca which holds information about whether
+ * sibling subcores are in Guest mode or host mode. The in_guest[] array
+ * is of size MAX_SUBCORE_PER_CORE=4, indexed using subcore id to set/unset
+ * subcore status. Only primary threads from each subcore is responsible
+ * to set/unset its designated array element while entering/exiting the
+ * guset.
+ *
+ * After invoking opal hmi handler call, one of the thread (of entire core)
+ * will need to resync the TB. Bit 63 from subcore state bitmap flags
+ * (sibling_subcore_state->flags) will be used to co-ordinate between
+ * primary threads to decide who takes up the responsibility.
+ *
+ * This is what we do:
+ * - Primary thread from each subcore tries to set resync required bit[63]
+ * of paca->sibling_subcore_state->flags.
+ * - The first primary thread that is able to set the flag takes the
+ * responsibility of TB resync. (Let us call it as thread leader)
+ * - All other threads which are in host will call
+ * wait_for_subcore_guest_exit() and wait for in_guest[0-3] from
+ * paca->sibling_subcore_state to get cleared.
+ * - All the primary thread will clear its subcore status from subcore
+ * state in_guest[] array respectively.
+ * - Once all primary threads clear in_guest[0-3], all of them will invoke
+ * opal hmi handler.
+ * - Now all threads will wait for TB resync to complete by invoking
+ * wait_for_tb_resync() except the thread leader.
+ * - Thread leader will do a TB resync by invoking opal_resync_timebase()
+ * call and the it will clear the resync required bit.
+ * - All other threads will now come out of resync wait loop and proceed
+ * with individual execution.
+ * - On return of this function, primary thread will signal all
+ * secondary threads to proceed.
+ * - All secondary threads will eventually call opal hmi handler on
+ * their exit path.
+ */
+
+long kvmppc_realmode_hmi_handler(void)
+{
+ int ptid = local_paca->kvm_hstate.ptid;
+ bool resync_req;
+
+ /* This is only called on primary thread. */
+ BUG_ON(ptid != 0);
+ __this_cpu_inc(irq_stat.hmi_exceptions);
+
+ /*
+ * By now primary thread has already completed guest->host
+ * partition switch but haven't signaled secondaries yet.
+ * All the secondary threads on this subcore is waiting
+ * for primary thread to signal them to go ahead.
+ *
+ * For threads from subcore which isn't in guest, they all will
+ * wait until all other subcores on this core exit the guest.
+ *
+ * Now set the resync required bit. If you are the first to
+ * set this bit then kvmppc_tb_resync_required() function will
+ * return true. For rest all other subcores
+ * kvmppc_tb_resync_required() will return false.
+ *
+ * If resync_req == true, then this thread is responsible to
+ * initiate TB resync after hmi handler has completed.
+ * All other threads on this core will wait until this thread
+ * clears the resync required bit flag.
+ */
+ resync_req = kvmppc_tb_resync_required();
+
+ /* Reset the subcore status to indicate it has exited guest */
+ kvmppc_subcore_exit_guest();
+
+ /*
+ * Wait for other subcores on this core to exit the guest.
+ * All the primary threads and threads from subcore that are
+ * not in guest will wait here until all subcores are out
+ * of guest context.
+ */
+ wait_for_subcore_guest_exit();
+
+ /*
+ * At this point we are sure that primary threads from each
+ * subcore on this core have completed guest->host partition
+ * switch. Now it is safe to call HMI handler.
+ */
+ if (ppc_md.hmi_exception_early)
+ ppc_md.hmi_exception_early(NULL);
+
+ /*
+ * Check if this thread is responsible to resync TB.
+ * All other threads will wait until this thread completes the
+ * TB resync.
+ */
+ if (resync_req) {
+ opal_resync_timebase();
+ /* Reset TB resync req bit */
+ kvmppc_tb_resync_done();
+ } else {
+ wait_for_tb_resync();
+ }
+ return 0;
+}
#include <asm/kvm_book3s_asm.h>
#include <asm/book3s/64/mmu-hash.h>
#include <asm/tm.h>
+#include <asm/opal.h>
#define VCPU_GPRS_TM(reg) (((reg) * ULONG_SIZE) + VCPU_GPR_TM)
lwsync
std r0, HSTATE_KVM_VCORE(r13)
+ /*
+ * All secondaries exiting guest will fall through this path.
+ * Before proceeding, just check for HMI interrupt and
+ * invoke opal hmi handler. By now we are sure that the
+ * primary thread on this core/subcore has already made partition
+ * switch/TB resync and we are good to call opal hmi handler.
+ */
+ cmpwi r12, BOOK3S_INTERRUPT_HMI
+ bne kvm_no_guest
+
+ li r3,0 /* NULL argument */
+ bl hmi_exception_realmode
/*
* At this point we have finished executing in the guest.
* We need to wait for hwthread_req to become zero, since
* whole-core mode, so we need to nap.
*/
kvm_unsplit_nap:
+ /*
+ * When secondaries are napping in kvm_unsplit_nap() with
+ * hwthread_req = 1, HMI goes ignored even though subcores are
+ * already exited the guest. Hence HMI keeps waking up secondaries
+ * from nap in a loop and secondaries always go back to nap since
+ * no vcore is assigned to them. This makes impossible for primary
+ * thread to get hold of secondary threads resulting into a soft
+ * lockup in KVM path.
+ *
+ * Let us check if HMI is pending and handle it before we go to nap.
+ */
+ cmpwi r12, BOOK3S_INTERRUPT_HMI
+ bne 55f
+ li r3, 0 /* NULL argument */
+ bl hmi_exception_realmode
+55:
/*
* Ensure that secondary doesn't nap when it has
* its vcore pointer set.
mtspr SPRN_DPDES, r8
END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S)
+ /* Mark the subcore state as inside guest */
+ bl kvmppc_subcore_enter_guest
+ nop
+ ld r5, HSTATE_KVM_VCORE(r13)
+ ld r4, HSTATE_KVM_VCPU(r13)
li r0,1
stb r0,VCORE_IN_GUEST(r5) /* signal secondaries to continue */
mtspr SPRN_DPDES, r8
END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S)
+ /* If HMI, call kvmppc_realmode_hmi_handler() */
+ cmpwi r12, BOOK3S_INTERRUPT_HMI
+ bne 27f
+ bl kvmppc_realmode_hmi_handler
+ nop
+ li r12, BOOK3S_INTERRUPT_HMI
+ /*
+ * At this point kvmppc_realmode_hmi_handler would have resync-ed
+ * the TB. Hence it is not required to subtract guest timebase
+ * offset from timebase. So, skip it.
+ *
+ * Also, do not call kvmppc_subcore_exit_guest() because it has
+ * been invoked as part of kvmppc_realmode_hmi_handler().
+ */
+ b 30f
+
+27:
/* Subtract timebase offset from timebase */
ld r8,VCORE_TB_OFFSET(r5)
cmpdi r8,0
addis r8,r8,0x100 /* if so, increment upper 40 bits */
mtspr SPRN_TBU40,r8
+17: bl kvmppc_subcore_exit_guest
+ nop
+30: ld r5,HSTATE_KVM_VCORE(r13)
+ ld r4,VCORE_KVM(r5) /* pointer to struct kvm */
+
/* Reset PCR */
-17: ld r0, VCORE_PCR(r5)
+ ld r0, VCORE_PCR(r5)
cmpdi r0, 0
beq 18f
li r0, 0
cmpwi r6, 3 /* hypervisor doorbell? */
beq 3f
END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S)
+ cmpwi r6, 0xa /* Hypervisor maintenance ? */
+ beq 4f
li r3, 1 /* anything else, return 1 */
0: blr
li r3, -1
blr
+ /* Woken up due to Hypervisor maintenance interrupt */
+4: li r12, BOOK3S_INTERRUPT_HMI
+ li r3, 1
+ blr
+
/*
* Determine what sort of external interrupt is pending (if any).
* Returns:
int emul;
program_interrupt:
- flags = vcpu->arch.shadow_srr1 & 0x1f0000ull;
+ /*
+ * shadow_srr1 only contains valid flags if we came here via
+ * a program exception. The other exceptions (emulation assist,
+ * FP unavailable, etc.) do not provide flags in SRR1, so use
+ * an illegal-instruction exception when injecting a program
+ * interrupt into the guest.
+ */
+ if (exit_nr == BOOK3S_INTERRUPT_PROGRAM)
+ flags = vcpu->arch.shadow_srr1 & 0x1f0000ull;
+ else
+ flags = SRR1_PROGILL;
emul = kvmppc_get_last_inst(vcpu, INST_GENERIC, &last_inst);
if (emul != EMULATE_DONE) {
advance = 0;
printk(KERN_ERR "Couldn't emulate instruction 0x%08x "
"(op %d xop %d)\n", inst, get_op(inst), get_xop(inst));
- kvmppc_core_queue_program(vcpu, 0);
}
}
OPAL_BRANCH(opal_tracepoint_entry) \
mfcr r12; \
stw r12,8(r1); \
- std r1,PACAR1(r13); \
li r11,0; \
mfmsr r12; \
ori r11,r11,MSR_EE; \
mfcr r12
std r11,16(r1)
stw r12,8(r1)
- std r1,PACAR1(r13)
li r11,0
mfmsr r12
ori r11,r11,MSR_EE
projects / cascardo / linux.git / commitdiff