[PATCH v4 00/53] KVM: PPC: Book3S HV P9: entry/exit optimisations

[PATCH v4 00/53] KVM: PPC: Book3S HV P9: entry/exit optimisations

[Nicholas Piggin]

This reduces radix guest full entry/exit latency on POWER9 and POWER10
by 2x.

Nested HV guests should see smaller improvements in their L1 entry/exit,
but this is also combined with most L0 speedups also applying to nested
entry. nginx localhost throughput test in a SMP nested guest is improved
about 10% (in a direct guest it doesn't change much because it uses XIVE
for IPIs) when L0 and L1 are patched.

It does this in several main ways:

- Rearrange code to optimise SPR accesses. Mainly, avoid scoreboard
  stalls.

- Test SPR values to avoid mtSPRs where possible. mtSPRs are expensive.

- Reduce mftb. mftb is expensive.

- Demand fault certain facilities to avoid saving and/or restoring them
  (at the cost of fault when they are used, but this is mitigated over
  a number of entries, like the facilities when context switching 
  processes). PM, TM, and EBB so far.

- Defer some sequences that are made just in case a guest is interrupted
  in the middle of a critical section to the case where the guest is
  scheduled on a different CPU, rather than every time (at the cost of
  an extra IPI in this case). Namely the tlbsync sequence for radix with
  GTSE, which is very expensive.

- Reduce locking, barriers, atomics related to the vcpus-per-vcore > 1
  handling that the P9 path does not require.

Changes since v3:
- Fix a possible bug in "Avoid tlbsync sequence on radix guest exit"
  where the TLB flushing optimisation (1 thread TLBIEL flushes TLB for
  entire core) might break because 'ptesync' was no longer guaranteed
  to be executed on all threads (via regular exit path). Now the TLB
  flush keeps track of all threads and whether they need to do a TLBIEL
  or a PTESYNC. Fixing this requires a new patch "Split P8 from P9 path
  guest vCPU TLB flushing".

Changes since v2:
- Rebased, several patches from the series were merged in the previous
  merge window.
- Fixed some compile errors noticed by kernel test robot.
- Added RB from Athira for the PMU stuff (thanks!)
- Split TIDR ftr check (patch 2) out into its own patch.
- Added a missed license tag on new file.

Changes since v1:
- Verified DPDES changes still work with msgsndp SMT emulation.
- Fixed HMI handling bug.
- Split softpatch handling fixes into smaller pieces.
- Rebased with Fabiano's latest HV sanitising patches.
- Fix TM demand faulting bug causing nested guest TM tests to TM Bad
  Thing the host in rare cases.
- Re-name new "pmu=" command line option to "pmu_override=" and update
  documentation wording.
- Add default=y config option rather than unconditionally removing the
  L0 nested PMU workaround.
- Remove unnecessary MSR[RI] updates in entry/exit. Down to about 4700
  cycles now.
- Another bugfix from Alexey's testing.

Changes since RFC:
- Rebased with Fabiano's HV sanitising patches at the front.
- Several demand faulting bug fixes mostly relating to nested guests.
- Removed facility demand-faulting from L0 nested entry/exit handler.
  Demand faulting is still done in the L1, but not the L0. The reason
  is to reduce complexity (although it's only a small amount of
  complexity), reduce demand faulting overhead that may require several

Thanks,
Nick

Nicholas Piggin (53):
  powerpc/64s: Remove WORT SPR from POWER9/10 (take 2)
  powerpc/64s: guard optional TIDR SPR with CPU ftr test
  KMV: PPC: Book3S HV P9: Use set_dec to set decrementer to host
  KVM: PPC: Book3S HV P9: Use host timer accounting to avoid decrementer
    read
  KVM: PPC: Book3S HV P9: Use large decrementer for HDEC
  KVM: PPC: Book3S HV P9: Reduce mftb per guest entry/exit
  powerpc/time: add API for KVM to re-arm the host timer/decrementer
  KVM: PPC: Book3S HV: POWER10 enable HAIL when running radix guests
  powerpc/64s: Keep AMOR SPR a constant ~0 at runtime
  KVM: PPC: Book3S HV: Don't always save PMU for guest capable of
    nesting
  powerpc/64s: Always set PMU control registers to frozen/disabled when
    not in use
  powerpc/64s: Implement PMU override command line option
  KVM: PPC: Book3S HV P9: Implement PMU save/restore in C
  KVM: PPC: Book3S HV P9: Factor PMU save/load into context switch
    functions
  KVM: PPC: Book3S HV P9: Demand fault PMU SPRs when marked not inuse
  KVM: PPC: Book3S HV P9: Factor out yield_count increment
  KVM: PPC: Book3S HV: CTRL SPR does not require read-modify-write
  KVM: PPC: Book3S HV P9: Move SPRG restore to restore_p9_host_os_sprs
  KVM: PPC: Book3S HV P9: Reduce mtmsrd instructions required to save
    host SPRs
  KVM: PPC: Book3S HV P9: Improve mtmsrd scheduling by delaying MSR[EE]
    disable
  KVM: PPC: Book3S HV P9: Add kvmppc_stop_thread to match
    kvmppc_start_thread
  KVM: PPC: Book3S HV: Change dec_expires to be relative to guest
    timebase
  KVM: PPC: Book3S HV P9: Move TB updates
  KVM: PPC: Book3S HV P9: Optimise timebase reads
  KVM: PPC: Book3S HV P9: Avoid SPR scoreboard stalls
  KVM: PPC: Book3S HV P9: Only execute mtSPR if the value changed
  KVM: PPC: Book3S HV P9: Juggle SPR switching around
  KVM: PPC: Book3S HV P9: Move vcpu register save/restore into functions
  KVM: PPC: Book3S HV P9: Move host OS save/restore functions to
    built-in
  KVM: PPC: Book3S HV P9: Move nested guest entry into its own function
  KVM: PPC: Book3S HV P9: Move remaining SPR and MSR access into low
    level entry
  KVM: PPC: Book3S HV P9: Implement TM fastpath for guest entry/exit
  KVM: PPC: Book3S HV P9: Switch PMU to guest as late as possible
  KVM: PPC: Book3S HV P9: Restrict DSISR canary workaround to processors
    that require it
  KVM: PPC: Book3S HV P9: More SPR speed improvements
  KVM: PPC: Book3S HV P9: Demand fault EBB facility registers
  KVM: PPC: Book3S HV P9: Demand fault TM facility registers
  KVM: PPC: Book3S HV P9: Use Linux SPR save/restore to manage some host
    SPRs
  KVM: PPC: Book3S HV P9: Comment and fix MMU context switching code
  KVM: PPC: Book3S HV P9: Test dawr_enabled() before saving host DAWR
    SPRs
  KVM: PPC: Book3S HV P9: Don't restore PSSCR if not needed
  KVM: PPC: Book3S HV: Split P8 from P9 path guest vCPU TLB flushing
  KVM: PPC: Book3S HV P9: Avoid tlbsync sequence on radix guest exit
  KVM: PPC: Book3S HV Nested: Avoid extra mftb() in nested entry
  KVM: PPC: Book3S HV P9: Improve mfmsr performance on entry
  KVM: PPC: Book3S HV P9: Optimise hash guest SLB saving
  KVM: PPC: Book3S HV P9: Avoid changing MSR[RI] in entry and exit
  KVM: PPC: Book3S HV P9: Add unlikely annotation for !mmu_ready
  KVM: PPC: Book3S HV P9: Avoid cpu_in_guest atomics on entry and exit
  KVM: PPC: Book3S HV P9: Remove most of the vcore logic
  KVM: PPC: Book3S HV P9: Tidy kvmppc_create_dtl_entry
  KVM: PPC: Book3S HV P9: Stop using vc->dpdes
  KVM: PPC: Book3S HV P9: Remove subcore HMI handling

 .../admin-guide/kernel-parameters.txt         |   8 +
 arch/powerpc/include/asm/asm-prototypes.h     |   5 -
 arch/powerpc/include/asm/kvm_asm.h            |   1 +
 arch/powerpc/include/asm/kvm_book3s.h         |   6 +
 arch/powerpc/include/asm/kvm_book3s_64.h      |   5 +-
 arch/powerpc/include/asm/kvm_host.h           |   7 +-
 arch/powerpc/include/asm/kvm_ppc.h            |   4 +-
 arch/powerpc/include/asm/switch_to.h          |   3 +
 arch/powerpc/include/asm/time.h               |  19 +-
 arch/powerpc/kernel/cpu_setup_power.c         |  12 +-
 arch/powerpc/kernel/dt_cpu_ftrs.c             |   8 +-
 arch/powerpc/kernel/process.c                 |  34 +
 arch/powerpc/kernel/time.c                    |  54 +-
 arch/powerpc/kvm/Kconfig                      |  15 +
 arch/powerpc/kvm/book3s_64_entry.S            |  11 +-
 arch/powerpc/kvm/book3s_64_mmu_radix.c        |   4 +
 arch/powerpc/kvm/book3s_hv.c                  | 851 +++++++++--------
 arch/powerpc/kvm/book3s_hv.h                  |  42 +
 arch/powerpc/kvm/book3s_hv_builtin.c          |  55 +-
 arch/powerpc/kvm/book3s_hv_hmi.c              |   7 +-
 arch/powerpc/kvm/book3s_hv_interrupts.S       |  13 +-
 arch/powerpc/kvm/book3s_hv_nested.c           |   8 +-
 arch/powerpc/kvm/book3s_hv_p9_entry.c         | 898 +++++++++++++++---
 arch/powerpc/kvm/book3s_hv_ras.c              |  54 ++
 arch/powerpc/kvm/book3s_hv_rm_mmu.c           |   6 -
 arch/powerpc/kvm/book3s_hv_rmhandlers.S       |  73 +-
 arch/powerpc/mm/book3s64/radix_pgtable.c      |  15 -
 arch/powerpc/perf/core-book3s.c               |  35 +
 arch/powerpc/platforms/powernv/idle.c         |   9 +-
 arch/powerpc/xmon/xmon.c                      |  10 +-
 30 files changed, 1555 insertions(+), 717 deletions(-)
 create mode 100644 arch/powerpc/kvm/book3s_hv.h

-- 
2.23.0

[PATCH v4 01/53] powerpc/64s: Remove WORT SPR from POWER9/10 (take 2)

[Nicholas Piggin]

This removes a missed remnant of the WORT SPR.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/platforms/powernv/idle.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/arch/powerpc/platforms/powernv/idle.c b/arch/powerpc/platforms/powernv/idle.c
index e3ffdc8e8567..86e787502e42 100644
--- a/arch/powerpc/platforms/powernv/idle.c
+++ b/arch/powerpc/platforms/powernv/idle.c
@@ -589,7 +589,6 @@ struct p9_sprs {
 	u64 purr;
 	u64 spurr;
 	u64 dscr;
-	u64 wort;
 	u64 ciabr;
 
 	u64 mmcra;
-- 
2.23.0

[PATCH v4 02/53] powerpc/64s: guard optional TIDR SPR with CPU ftr test

[Nicholas Piggin]

The TIDR SPR only exists on POWER9. Avoid accessing it when the
feature bit for it is not set.

Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/kvm/book3s_hv.c | 12 ++++++++----
 arch/powerpc/xmon/xmon.c     | 10 ++++++++--
 2 files changed, 16 insertions(+), 6 deletions(-)

diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 7b74fc0a986b..2777f66001a8 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -3780,7 +3780,8 @@ static void load_spr_state(struct kvm_vcpu *vcpu)
 	mtspr(SPRN_EBBHR, vcpu->arch.ebbhr);
 	mtspr(SPRN_EBBRR, vcpu->arch.ebbrr);
 	mtspr(SPRN_BESCR, vcpu->arch.bescr);
-	mtspr(SPRN_TIDR, vcpu->arch.tid);
+	if (cpu_has_feature(CPU_FTR_P9_TIDR))
+		mtspr(SPRN_TIDR, vcpu->arch.tid);
 	mtspr(SPRN_AMR, vcpu->arch.amr);
 	mtspr(SPRN_UAMOR, vcpu->arch.uamor);
 
@@ -3806,7 +3807,8 @@ static void store_spr_state(struct kvm_vcpu *vcpu)
 	vcpu->arch.ebbhr = mfspr(SPRN_EBBHR);
 	vcpu->arch.ebbrr = mfspr(SPRN_EBBRR);
 	vcpu->arch.bescr = mfspr(SPRN_BESCR);
-	vcpu->arch.tid = mfspr(SPRN_TIDR);
+	if (cpu_has_feature(CPU_FTR_P9_TIDR))
+		vcpu->arch.tid = mfspr(SPRN_TIDR);
 	vcpu->arch.amr = mfspr(SPRN_AMR);
 	vcpu->arch.uamor = mfspr(SPRN_UAMOR);
 	vcpu->arch.dscr = mfspr(SPRN_DSCR);
@@ -3826,7 +3828,8 @@ struct p9_host_os_sprs {
 static void save_p9_host_os_sprs(struct p9_host_os_sprs *host_os_sprs)
 {
 	host_os_sprs->dscr = mfspr(SPRN_DSCR);
-	host_os_sprs->tidr = mfspr(SPRN_TIDR);
+	if (cpu_has_feature(CPU_FTR_P9_TIDR))
+		host_os_sprs->tidr = mfspr(SPRN_TIDR);
 	host_os_sprs->iamr = mfspr(SPRN_IAMR);
 	host_os_sprs->amr = mfspr(SPRN_AMR);
 	host_os_sprs->fscr = mfspr(SPRN_FSCR);
@@ -3840,7 +3843,8 @@ static void restore_p9_host_os_sprs(struct kvm_vcpu *vcpu,
 	mtspr(SPRN_UAMOR, 0);
 
 	mtspr(SPRN_DSCR, host_os_sprs->dscr);
-	mtspr(SPRN_TIDR, host_os_sprs->tidr);
+	if (cpu_has_feature(CPU_FTR_P9_TIDR))
+		mtspr(SPRN_TIDR, host_os_sprs->tidr);
 	mtspr(SPRN_IAMR, host_os_sprs->iamr);
 
 	if (host_os_sprs->amr != vcpu->arch.amr)
diff --git a/arch/powerpc/xmon/xmon.c b/arch/powerpc/xmon/xmon.c
index 8b28ff9d98d1..83100c6524cc 100644
--- a/arch/powerpc/xmon/xmon.c
+++ b/arch/powerpc/xmon/xmon.c
@@ -2107,8 +2107,14 @@ static void dump_300_sprs(void)
 	if (!cpu_has_feature(CPU_FTR_ARCH_300))
 		return;
 
-	printf("pidr   = %.16lx  tidr  = %.16lx\n",
-		mfspr(SPRN_PID), mfspr(SPRN_TIDR));
+	if (cpu_has_feature(CPU_FTR_P9_TIDR)) {
+		printf("pidr   = %.16lx  tidr  = %.16lx\n",
+			mfspr(SPRN_PID), mfspr(SPRN_TIDR));
+	} else {
+		printf("pidr   = %.16lx\n",
+			mfspr(SPRN_PID));
+	}
+
 	printf("psscr  = %.16lx\n",
 		hv ? mfspr(SPRN_PSSCR) : mfspr(SPRN_PSSCR_PR));
 
-- 
2.23.0

[PATCH v4 03/53] KMV: PPC: Book3S HV P9: Use set_dec to set decrementer to host

[Nicholas Piggin]

The host Linux timer code arms the decrementer with the value
'decrementers_next_tb - current_tb' using set_dec(), which stores
val - 1 on Book3S-64, which is not quite the same as what KVM does
to re-arm the host decrementer when exiting the guest.

This shouldn't be a significant change, but it makes the logic match
and avoids this small extra change being brought into the next patch.

Suggested-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/kvm/book3s_hv.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 2777f66001a8..c7dbdec183b9 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -4063,7 +4063,7 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
 	vc->entry_exit_map = 0x101;
 	vc->in_guest = 0;
 
-	mtspr(SPRN_DEC, local_paca->kvm_hstate.dec_expires - mftb());
+	set_dec(local_paca->kvm_hstate.dec_expires - mftb());
 	/* We may have raced with new irq work */
 	if (test_irq_work_pending())
 		set_dec(1);
-- 
2.23.0

[PATCH v4 04/53] KVM: PPC: Book3S HV P9: Use host timer accounting to avoid decrementer read

[Nicholas Piggin]

There is no need to save away the host DEC value, as it is derived
from the host timer subsystem which maintains the next timer time,
so it can be restored from there.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/include/asm/time.h |  5 +++++
 arch/powerpc/kernel/time.c      |  1 +
 arch/powerpc/kvm/book3s_hv.c    | 14 +++++++-------
 3 files changed, 13 insertions(+), 7 deletions(-)

diff --git a/arch/powerpc/include/asm/time.h b/arch/powerpc/include/asm/time.h
index 8c2c3dd4ddba..fd09b4797fd7 100644
--- a/arch/powerpc/include/asm/time.h
+++ b/arch/powerpc/include/asm/time.h
@@ -111,6 +111,11 @@ static inline unsigned long test_irq_work_pending(void)
 
 DECLARE_PER_CPU(u64, decrementers_next_tb);
 
+static inline u64 timer_get_next_tb(void)
+{
+	return __this_cpu_read(decrementers_next_tb);
+}
+
 /* Convert timebase ticks to nanoseconds */
 unsigned long long tb_to_ns(unsigned long long tb_ticks);
 
diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c
index cae8f03a44fe..374950afec2f 100644
--- a/arch/powerpc/kernel/time.c
+++ b/arch/powerpc/kernel/time.c
@@ -107,6 +107,7 @@ struct clock_event_device decrementer_clockevent = {
 EXPORT_SYMBOL(decrementer_clockevent);
 
 DEFINE_PER_CPU(u64, decrementers_next_tb);
+EXPORT_SYMBOL_GPL(decrementers_next_tb);
 static DEFINE_PER_CPU(struct clock_event_device, decrementers);
 
 #define XSEC_PER_SEC (1024*1024)
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index c7dbdec183b9..3322edbafc64 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -3873,18 +3873,17 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
 	struct kvmppc_vcore *vc = vcpu->arch.vcore;
 	struct p9_host_os_sprs host_os_sprs;
 	s64 dec;
-	u64 tb;
+	u64 tb, next_timer;
 	int trap, save_pmu;
 
 	WARN_ON_ONCE(vcpu->arch.ceded);
 
-	dec = mfspr(SPRN_DEC);
 	tb = mftb();
-	if (dec < 0)
+	next_timer = timer_get_next_tb();
+	if (tb >= next_timer)
 		return BOOK3S_INTERRUPT_HV_DECREMENTER;
-	local_paca->kvm_hstate.dec_expires = dec + tb;
-	if (local_paca->kvm_hstate.dec_expires < time_limit)
-		time_limit = local_paca->kvm_hstate.dec_expires;
+	if (next_timer < time_limit)
+		time_limit = next_timer;
 
 	save_p9_host_os_sprs(&host_os_sprs);
 
@@ -4063,7 +4062,8 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
 	vc->entry_exit_map = 0x101;
 	vc->in_guest = 0;
 
-	set_dec(local_paca->kvm_hstate.dec_expires - mftb());
+	next_timer = timer_get_next_tb();
+	set_dec(next_timer - mftb());
 	/* We may have raced with new irq work */
 	if (test_irq_work_pending())
 		set_dec(1);
-- 
2.23.0

[PATCH v4 05/53] KVM: PPC: Book3S HV P9: Use large decrementer for HDEC

[Nicholas Piggin]

On processors that don't suppress the HDEC exceptions when LPCR[HDICE]=0,
this could help reduce needless guest exits due to leftover exceptions on
entering the guest.

Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/include/asm/time.h       | 2 ++
 arch/powerpc/kernel/time.c            | 1 +
 arch/powerpc/kvm/book3s_hv_p9_entry.c | 3 ++-
 3 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/include/asm/time.h b/arch/powerpc/include/asm/time.h
index fd09b4797fd7..69b6be617772 100644
--- a/arch/powerpc/include/asm/time.h
+++ b/arch/powerpc/include/asm/time.h
@@ -18,6 +18,8 @@
 #include <asm/vdso/timebase.h>
 
 /* time.c */
+extern u64 decrementer_max;
+
 extern unsigned long tb_ticks_per_jiffy;
 extern unsigned long tb_ticks_per_usec;
 extern unsigned long tb_ticks_per_sec;
diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c
index 374950afec2f..2769d565f842 100644
--- a/arch/powerpc/kernel/time.c
+++ b/arch/powerpc/kernel/time.c
@@ -88,6 +88,7 @@ static struct clocksource clocksource_timebase = {
 
 #define DECREMENTER_DEFAULT_MAX 0x7FFFFFFF
 u64 decrementer_max = DECREMENTER_DEFAULT_MAX;
+EXPORT_SYMBOL_GPL(decrementer_max); /* for KVM HDEC */
 
 static int decrementer_set_next_event(unsigned long evt,
 				      struct clock_event_device *dev);
diff --git a/arch/powerpc/kvm/book3s_hv_p9_entry.c b/arch/powerpc/kvm/book3s_hv_p9_entry.c
index 961b3d70483c..0ff9ddb5e7ca 100644
--- a/arch/powerpc/kvm/book3s_hv_p9_entry.c
+++ b/arch/powerpc/kvm/book3s_hv_p9_entry.c
@@ -504,7 +504,8 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
 		vc->tb_offset_applied = 0;
 	}
 
-	mtspr(SPRN_HDEC, 0x7fffffff);
+	/* HDEC must be at least as large as DEC, so decrementer_max fits */
+	mtspr(SPRN_HDEC, decrementer_max);
 
 	save_clear_guest_mmu(kvm, vcpu);
 	switch_mmu_to_host(kvm, host_pidr);
-- 
2.23.0

[PATCH v4 06/53] KVM: PPC: Book3S HV P9: Reduce mftb per guest entry/exit

[Nicholas Piggin]

mftb is serialising (dispatch next-to-complete) so it is heavy weight
for a mfspr. Avoid reading it multiple times in the entry or exit paths.
A small number of cycles delay to timers is tolerable.

Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/kvm/book3s_hv.c          | 4 ++--
 arch/powerpc/kvm/book3s_hv_p9_entry.c | 5 +++--
 2 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 3322edbafc64..5fc0c168a39a 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -3940,7 +3940,7 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
 	 *
 	 * XXX: Another day's problem.
 	 */
-	mtspr(SPRN_DEC, vcpu->arch.dec_expires - mftb());
+	mtspr(SPRN_DEC, vcpu->arch.dec_expires - tb);
 
 	if (kvmhv_on_pseries()) {
 		/*
@@ -4063,7 +4063,7 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
 	vc->in_guest = 0;
 
 	next_timer = timer_get_next_tb();
-	set_dec(next_timer - mftb());
+	set_dec(next_timer - tb);
 	/* We may have raced with new irq work */
 	if (test_irq_work_pending())
 		set_dec(1);
diff --git a/arch/powerpc/kvm/book3s_hv_p9_entry.c b/arch/powerpc/kvm/book3s_hv_p9_entry.c
index 0ff9ddb5e7ca..bd8cf0a65ce8 100644
--- a/arch/powerpc/kvm/book3s_hv_p9_entry.c
+++ b/arch/powerpc/kvm/book3s_hv_p9_entry.c
@@ -203,7 +203,8 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
 	unsigned long host_dawr1;
 	unsigned long host_dawrx1;
 
-	hdec = time_limit - mftb();
+	tb = mftb();
+	hdec = time_limit - tb;
 	if (hdec < 0)
 		return BOOK3S_INTERRUPT_HV_DECREMENTER;
 
@@ -215,7 +216,7 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
 	vcpu->arch.ceded = 0;
 
 	if (vc->tb_offset) {
-		u64 new_tb = mftb() + vc->tb_offset;
+		u64 new_tb = tb + vc->tb_offset;
 		mtspr(SPRN_TBU40, new_tb);
 		tb = mftb();
 		if ((tb & 0xffffff) < (new_tb & 0xffffff))
-- 
2.23.0

[PATCH v4 07/53] powerpc/time: add API for KVM to re-arm the host timer/decrementer

[Nicholas Piggin]

Rather than have KVM look up the host timer and fiddle with the
irq-work internal details, have the powerpc/time.c code provide a
function for KVM to re-arm the Linux timer code when exiting a
guest.

This is implementation has an improvement over existing code of
marking a decrementer interrupt as soft-pending if a timer has
expired, rather than setting DEC to a -ve value, which tended to
cause host timers to take two interrupts (first hdec to exit the
guest, then the immediate dec).

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/include/asm/time.h | 16 +++-------
 arch/powerpc/kernel/time.c      | 52 +++++++++++++++++++++++++++------
 arch/powerpc/kvm/book3s_hv.c    |  7 ++---
 3 files changed, 49 insertions(+), 26 deletions(-)

diff --git a/arch/powerpc/include/asm/time.h b/arch/powerpc/include/asm/time.h
index 69b6be617772..924b2157882f 100644
--- a/arch/powerpc/include/asm/time.h
+++ b/arch/powerpc/include/asm/time.h
@@ -99,18 +99,6 @@ extern void div128_by_32(u64 dividend_high, u64 dividend_low,
 extern void secondary_cpu_time_init(void);
 extern void __init time_init(void);
 
-#ifdef CONFIG_PPC64
-static inline unsigned long test_irq_work_pending(void)
-{
-	unsigned long x;
-
-	asm volatile("lbz %0,%1(13)"
-		: "=r" (x)
-		: "i" (offsetof(struct paca_struct, irq_work_pending)));
-	return x;
-}
-#endif
-
 DECLARE_PER_CPU(u64, decrementers_next_tb);
 
 static inline u64 timer_get_next_tb(void)
@@ -118,6 +106,10 @@ static inline u64 timer_get_next_tb(void)
 	return __this_cpu_read(decrementers_next_tb);
 }
 
+#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
+void timer_rearm_host_dec(u64 now);
+#endif
+
 /* Convert timebase ticks to nanoseconds */
 unsigned long long tb_to_ns(unsigned long long tb_ticks);
 
diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c
index 2769d565f842..f7cddb82938f 100644
--- a/arch/powerpc/kernel/time.c
+++ b/arch/powerpc/kernel/time.c
@@ -498,6 +498,16 @@ EXPORT_SYMBOL(profile_pc);
  * 64-bit uses a byte in the PACA, 32-bit uses a per-cpu variable...
  */
 #ifdef CONFIG_PPC64
+static inline unsigned long test_irq_work_pending(void)
+{
+	unsigned long x;
+
+	asm volatile("lbz %0,%1(13)"
+		: "=r" (x)
+		: "i" (offsetof(struct paca_struct, irq_work_pending)));
+	return x;
+}
+
 static inline void set_irq_work_pending_flag(void)
 {
 	asm volatile("stb %0,%1(13)" : :
@@ -541,13 +551,44 @@ void arch_irq_work_raise(void)
 	preempt_enable();
 }
 
+static void set_dec_or_work(u64 val)
+{
+	set_dec(val);
+	/* We may have raced with new irq work */
+	if (unlikely(test_irq_work_pending()))
+		set_dec(1);
+}
+
 #else  /* CONFIG_IRQ_WORK */
 
 #define test_irq_work_pending()	0
 #define clear_irq_work_pending()
 
+static void set_dec_or_work(u64 val)
+{
+	set_dec(val);
+}
 #endif /* CONFIG_IRQ_WORK */
 
+#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
+void timer_rearm_host_dec(u64 now)
+{
+	u64 *next_tb = this_cpu_ptr(&decrementers_next_tb);
+
+	WARN_ON_ONCE(!arch_irqs_disabled());
+	WARN_ON_ONCE(mfmsr() & MSR_EE);
+
+	if (now >= *next_tb) {
+		local_paca->irq_happened |= PACA_IRQ_DEC;
+	} else {
+		now = *next_tb - now;
+		if (now <= decrementer_max)
+			set_dec_or_work(now);
+	}
+}
+EXPORT_SYMBOL_GPL(timer_rearm_host_dec);
+#endif
+
 /*
  * timer_interrupt - gets called when the decrementer overflows,
  * with interrupts disabled.
@@ -608,10 +649,7 @@ DEFINE_INTERRUPT_HANDLER_ASYNC(timer_interrupt)
 	} else {
 		now = *next_tb - now;
 		if (now <= decrementer_max)
-			set_dec(now);
-		/* We may have raced with new irq work */
-		if (test_irq_work_pending())
-			set_dec(1);
+			set_dec_or_work(now);
 		__this_cpu_inc(irq_stat.timer_irqs_others);
 	}
 
@@ -845,11 +883,7 @@ static int decrementer_set_next_event(unsigned long evt,
 				      struct clock_event_device *dev)
 {
 	__this_cpu_write(decrementers_next_tb, get_tb() + evt);
-	set_dec(evt);
-
-	/* We may have raced with new irq work */
-	if (test_irq_work_pending())
-		set_dec(1);
+	set_dec_or_work(evt);
 
 	return 0;
 }
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 5fc0c168a39a..1b556dbfcfc8 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -4062,11 +4062,8 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
 	vc->entry_exit_map = 0x101;
 	vc->in_guest = 0;
 
-	next_timer = timer_get_next_tb();
-	set_dec(next_timer - tb);
-	/* We may have raced with new irq work */
-	if (test_irq_work_pending())
-		set_dec(1);
+	timer_rearm_host_dec(tb);
+
 	mtspr(SPRN_SPRG_VDSO_WRITE, local_paca->sprg_vdso);
 
 	kvmhv_load_host_pmu();
-- 
2.23.0

[PATCH v4 08/53] KVM: PPC: Book3S HV: POWER10 enable HAIL when running radix guests

[Nicholas Piggin]

HV interrupts may be taken with the MMU enabled when radix guests are
running. Enable LPCR[HAIL] on ISA v3.1 processors for radix guests.
Make this depend on the host LPCR[HAIL] being enabled. Currently that is
always enabled, but having this test means any issue that might require
LPCR[HAIL] to be disabled in the host will not have to be duplicated in
KVM.

This optimisation takes 1380 cycles off a NULL hcall entry+exit micro
benchmark on a POWER10.

Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/kvm/book3s_hv.c | 29 +++++++++++++++++++++++++----
 1 file changed, 25 insertions(+), 4 deletions(-)

diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 1b556dbfcfc8..a683ee5f420a 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -5073,6 +5073,8 @@ static int kvmppc_hv_setup_htab_rma(struct kvm_vcpu *vcpu)
  */
 int kvmppc_switch_mmu_to_hpt(struct kvm *kvm)
 {
+	unsigned long lpcr, lpcr_mask;
+
 	if (nesting_enabled(kvm))
 		kvmhv_release_all_nested(kvm);
 	kvmppc_rmap_reset(kvm);
@@ -5082,8 +5084,13 @@ int kvmppc_switch_mmu_to_hpt(struct kvm *kvm)
 	kvm->arch.radix = 0;
 	spin_unlock(&kvm->mmu_lock);
 	kvmppc_free_radix(kvm);
-	kvmppc_update_lpcr(kvm, LPCR_VPM1,
-			   LPCR_VPM1 | LPCR_UPRT | LPCR_GTSE | LPCR_HR);
+
+	lpcr = LPCR_VPM1;
+	lpcr_mask = LPCR_VPM1 | LPCR_UPRT | LPCR_GTSE | LPCR_HR;
+	if (cpu_has_feature(CPU_FTR_ARCH_31))
+		lpcr_mask |= LPCR_HAIL;
+	kvmppc_update_lpcr(kvm, lpcr, lpcr_mask);
+
 	return 0;
 }
 
@@ -5093,6 +5100,7 @@ int kvmppc_switch_mmu_to_hpt(struct kvm *kvm)
  */
 int kvmppc_switch_mmu_to_radix(struct kvm *kvm)
 {
+	unsigned long lpcr, lpcr_mask;
 	int err;
 
 	err = kvmppc_init_vm_radix(kvm);
@@ -5104,8 +5112,17 @@ int kvmppc_switch_mmu_to_radix(struct kvm *kvm)
 	kvm->arch.radix = 1;
 	spin_unlock(&kvm->mmu_lock);
 	kvmppc_free_hpt(&kvm->arch.hpt);
-	kvmppc_update_lpcr(kvm, LPCR_UPRT | LPCR_GTSE | LPCR_HR,
-			   LPCR_VPM1 | LPCR_UPRT | LPCR_GTSE | LPCR_HR);
+
+	lpcr = LPCR_UPRT | LPCR_GTSE | LPCR_HR;
+	lpcr_mask = LPCR_VPM1 | LPCR_UPRT | LPCR_GTSE | LPCR_HR;
+	if (cpu_has_feature(CPU_FTR_ARCH_31)) {
+		lpcr_mask |= LPCR_HAIL;
+		if (cpu_has_feature(CPU_FTR_HVMODE) &&
+				(kvm->arch.host_lpcr & LPCR_HAIL))
+			lpcr |= LPCR_HAIL;
+	}
+	kvmppc_update_lpcr(kvm, lpcr, lpcr_mask);
+
 	return 0;
 }
 
@@ -5269,6 +5286,10 @@ static int kvmppc_core_init_vm_hv(struct kvm *kvm)
 		kvm->arch.mmu_ready = 1;
 		lpcr &= ~LPCR_VPM1;
 		lpcr |= LPCR_UPRT | LPCR_GTSE | LPCR_HR;
+		if (cpu_has_feature(CPU_FTR_HVMODE) &&
+		    cpu_has_feature(CPU_FTR_ARCH_31) &&
+		    (kvm->arch.host_lpcr & LPCR_HAIL))
+			lpcr |= LPCR_HAIL;
 		ret = kvmppc_init_vm_radix(kvm);
 		if (ret) {
 			kvmppc_free_lpid(kvm->arch.lpid);
-- 
2.23.0

[PATCH v4 09/53] powerpc/64s: Keep AMOR SPR a constant ~0 at runtime

[Nicholas Piggin]

This register controls supervisor SPR modifications, and as such is only
relevant for KVM. KVM always sets AMOR to ~0 on guest entry, and never
restores it coming back out to the host, so it can be kept constant and
avoid the mtSPR in KVM guest entry.

Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/kernel/cpu_setup_power.c    |  8 ++++++++
 arch/powerpc/kernel/dt_cpu_ftrs.c        |  2 ++
 arch/powerpc/kvm/book3s_hv_p9_entry.c    |  2 --
 arch/powerpc/kvm/book3s_hv_rmhandlers.S  |  2 --
 arch/powerpc/mm/book3s64/radix_pgtable.c | 15 ---------------
 arch/powerpc/platforms/powernv/idle.c    |  8 +++-----
 6 files changed, 13 insertions(+), 24 deletions(-)

diff --git a/arch/powerpc/kernel/cpu_setup_power.c b/arch/powerpc/kernel/cpu_setup_power.c
index 3cca88ee96d7..a29dc8326622 100644
--- a/arch/powerpc/kernel/cpu_setup_power.c
+++ b/arch/powerpc/kernel/cpu_setup_power.c
@@ -137,6 +137,7 @@ void __setup_cpu_power7(unsigned long offset, struct cpu_spec *t)
 		return;
 
 	mtspr(SPRN_LPID, 0);
+	mtspr(SPRN_AMOR, ~0);
 	mtspr(SPRN_PCR, PCR_MASK);
 	init_LPCR_ISA206(mfspr(SPRN_LPCR), LPCR_LPES1 >> LPCR_LPES_SH);
 }
@@ -150,6 +151,7 @@ void __restore_cpu_power7(void)
 		return;
 
 	mtspr(SPRN_LPID, 0);
+	mtspr(SPRN_AMOR, ~0);
 	mtspr(SPRN_PCR, PCR_MASK);
 	init_LPCR_ISA206(mfspr(SPRN_LPCR), LPCR_LPES1 >> LPCR_LPES_SH);
 }
@@ -164,6 +166,7 @@ void __setup_cpu_power8(unsigned long offset, struct cpu_spec *t)
 		return;
 
 	mtspr(SPRN_LPID, 0);
+	mtspr(SPRN_AMOR, ~0);
 	mtspr(SPRN_PCR, PCR_MASK);
 	init_LPCR_ISA206(mfspr(SPRN_LPCR) | LPCR_PECEDH, 0); /* LPES = 0 */
 	init_HFSCR();
@@ -184,6 +187,7 @@ void __restore_cpu_power8(void)
 		return;
 
 	mtspr(SPRN_LPID, 0);
+	mtspr(SPRN_AMOR, ~0);
 	mtspr(SPRN_PCR, PCR_MASK);
 	init_LPCR_ISA206(mfspr(SPRN_LPCR) | LPCR_PECEDH, 0); /* LPES = 0 */
 	init_HFSCR();
@@ -202,6 +206,7 @@ void __setup_cpu_power9(unsigned long offset, struct cpu_spec *t)
 	mtspr(SPRN_PSSCR, 0);
 	mtspr(SPRN_LPID, 0);
 	mtspr(SPRN_PID, 0);
+	mtspr(SPRN_AMOR, ~0);
 	mtspr(SPRN_PCR, PCR_MASK);
 	init_LPCR_ISA300((mfspr(SPRN_LPCR) | LPCR_PECEDH | LPCR_PECE_HVEE |\
 			 LPCR_HVICE | LPCR_HEIC) & ~(LPCR_UPRT | LPCR_HR), 0);
@@ -223,6 +228,7 @@ void __restore_cpu_power9(void)
 	mtspr(SPRN_PSSCR, 0);
 	mtspr(SPRN_LPID, 0);
 	mtspr(SPRN_PID, 0);
+	mtspr(SPRN_AMOR, ~0);
 	mtspr(SPRN_PCR, PCR_MASK);
 	init_LPCR_ISA300((mfspr(SPRN_LPCR) | LPCR_PECEDH | LPCR_PECE_HVEE |\
 			 LPCR_HVICE | LPCR_HEIC) & ~(LPCR_UPRT | LPCR_HR), 0);
@@ -242,6 +248,7 @@ void __setup_cpu_power10(unsigned long offset, struct cpu_spec *t)
 	mtspr(SPRN_PSSCR, 0);
 	mtspr(SPRN_LPID, 0);
 	mtspr(SPRN_PID, 0);
+	mtspr(SPRN_AMOR, ~0);
 	mtspr(SPRN_PCR, PCR_MASK);
 	init_LPCR_ISA300((mfspr(SPRN_LPCR) | LPCR_PECEDH | LPCR_PECE_HVEE |\
 			 LPCR_HVICE | LPCR_HEIC) & ~(LPCR_UPRT | LPCR_HR), 0);
@@ -264,6 +271,7 @@ void __restore_cpu_power10(void)
 	mtspr(SPRN_PSSCR, 0);
 	mtspr(SPRN_LPID, 0);
 	mtspr(SPRN_PID, 0);
+	mtspr(SPRN_AMOR, ~0);
 	mtspr(SPRN_PCR, PCR_MASK);
 	init_LPCR_ISA300((mfspr(SPRN_LPCR) | LPCR_PECEDH | LPCR_PECE_HVEE |\
 			 LPCR_HVICE | LPCR_HEIC) & ~(LPCR_UPRT | LPCR_HR), 0);
diff --git a/arch/powerpc/kernel/dt_cpu_ftrs.c b/arch/powerpc/kernel/dt_cpu_ftrs.c
index ba527fb52993..de59971319ab 100644
--- a/arch/powerpc/kernel/dt_cpu_ftrs.c
+++ b/arch/powerpc/kernel/dt_cpu_ftrs.c
@@ -80,6 +80,7 @@ static void __restore_cpu_cpufeatures(void)
 	mtspr(SPRN_LPCR, system_registers.lpcr);
 	if (hv_mode) {
 		mtspr(SPRN_LPID, 0);
+		mtspr(SPRN_AMOR, ~0);
 		mtspr(SPRN_HFSCR, system_registers.hfscr);
 		mtspr(SPRN_PCR, system_registers.pcr);
 	}
@@ -216,6 +217,7 @@ static int __init feat_enable_hv(struct dt_cpu_feature *f)
 	}
 
 	mtspr(SPRN_LPID, 0);
+	mtspr(SPRN_AMOR, ~0);
 
 	lpcr = mfspr(SPRN_LPCR);
 	lpcr &=  ~LPCR_LPES0; /* HV external interrupts */
diff --git a/arch/powerpc/kvm/book3s_hv_p9_entry.c b/arch/powerpc/kvm/book3s_hv_p9_entry.c
index bd8cf0a65ce8..a7f63082b4e3 100644
--- a/arch/powerpc/kvm/book3s_hv_p9_entry.c
+++ b/arch/powerpc/kvm/book3s_hv_p9_entry.c
@@ -286,8 +286,6 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
 	mtspr(SPRN_SPRG2, vcpu->arch.shregs.sprg2);
 	mtspr(SPRN_SPRG3, vcpu->arch.shregs.sprg3);
 
-	mtspr(SPRN_AMOR, ~0UL);
-
 	local_paca->kvm_hstate.in_guest = KVM_GUEST_MODE_HV_P9;
 
 	/*
diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
index 32a4b4d412b9..c45ec4cd9d52 100644
--- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S
+++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
@@ -778,10 +778,8 @@ END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_207S)
 	/* Restore AMR and UAMOR, set AMOR to all 1s */
 	ld	r5,VCPU_AMR(r4)
 	ld	r6,VCPU_UAMOR(r4)
-	li	r7,-1
 	mtspr	SPRN_AMR,r5
 	mtspr	SPRN_UAMOR,r6
-	mtspr	SPRN_AMOR,r7
 
 	/* Restore state of CTRL run bit; assume 1 on entry */
 	lwz	r5,VCPU_CTRL(r4)
diff --git a/arch/powerpc/mm/book3s64/radix_pgtable.c b/arch/powerpc/mm/book3s64/radix_pgtable.c
index 3a600bd7fbc6..77820036c722 100644
--- a/arch/powerpc/mm/book3s64/radix_pgtable.c
+++ b/arch/powerpc/mm/book3s64/radix_pgtable.c
@@ -572,18 +572,6 @@ void __init radix__early_init_devtree(void)
 	return;
 }
 
-static void radix_init_amor(void)
-{
-	/*
-	* In HV mode, we init AMOR (Authority Mask Override Register) so that
-	* the hypervisor and guest can setup IAMR (Instruction Authority Mask
-	* Register), enable key 0 and set it to 1.
-	*
-	* AMOR = 0b1100 .... 0000 (Mask for key 0 is 11)
-	*/
-	mtspr(SPRN_AMOR, (3ul << 62));
-}
-
 void __init radix__early_init_mmu(void)
 {
 	unsigned long lpcr;
@@ -644,7 +632,6 @@ void __init radix__early_init_mmu(void)
 		lpcr = mfspr(SPRN_LPCR);
 		mtspr(SPRN_LPCR, lpcr | LPCR_UPRT | LPCR_HR);
 		radix_init_partition_table();
-		radix_init_amor();
 	} else {
 		radix_init_pseries();
 	}
@@ -668,8 +655,6 @@ void radix__early_init_mmu_secondary(void)
 
 		set_ptcr_when_no_uv(__pa(partition_tb) |
 				    (PATB_SIZE_SHIFT - 12));
-
-		radix_init_amor();
 	}
 
 	radix__switch_mmu_context(NULL, &init_mm);
diff --git a/arch/powerpc/platforms/powernv/idle.c b/arch/powerpc/platforms/powernv/idle.c
index 86e787502e42..3bc84e2fe064 100644
--- a/arch/powerpc/platforms/powernv/idle.c
+++ b/arch/powerpc/platforms/powernv/idle.c
@@ -306,8 +306,8 @@ struct p7_sprs {
 	/* per thread SPRs that get lost in shallow states */
 	u64 amr;
 	u64 iamr;
-	u64 amor;
 	u64 uamor;
+	/* amor is restored to constant ~0 */
 };
 
 static unsigned long power7_idle_insn(unsigned long type)
@@ -378,7 +378,6 @@ static unsigned long power7_idle_insn(unsigned long type)
 	if (cpu_has_feature(CPU_FTR_ARCH_207S)) {
 		sprs.amr	= mfspr(SPRN_AMR);
 		sprs.iamr	= mfspr(SPRN_IAMR);
-		sprs.amor	= mfspr(SPRN_AMOR);
 		sprs.uamor	= mfspr(SPRN_UAMOR);
 	}
 
@@ -397,7 +396,7 @@ static unsigned long power7_idle_insn(unsigned long type)
 			 */
 			mtspr(SPRN_AMR,		sprs.amr);
 			mtspr(SPRN_IAMR,	sprs.iamr);
-			mtspr(SPRN_AMOR,	sprs.amor);
+			mtspr(SPRN_AMOR,	~0);
 			mtspr(SPRN_UAMOR,	sprs.uamor);
 		}
 	}
@@ -686,7 +685,6 @@ static unsigned long power9_idle_stop(unsigned long psscr)
 
 	sprs.amr	= mfspr(SPRN_AMR);
 	sprs.iamr	= mfspr(SPRN_IAMR);
-	sprs.amor	= mfspr(SPRN_AMOR);
 	sprs.uamor	= mfspr(SPRN_UAMOR);
 
 	srr1 = isa300_idle_stop_mayloss(psscr);		/* go idle */
@@ -707,7 +705,7 @@ static unsigned long power9_idle_stop(unsigned long psscr)
 		 */
 		mtspr(SPRN_AMR,		sprs.amr);
 		mtspr(SPRN_IAMR,	sprs.iamr);
-		mtspr(SPRN_AMOR,	sprs.amor);
+		mtspr(SPRN_AMOR,	~0);
 		mtspr(SPRN_UAMOR,	sprs.uamor);
 
 		/*
-- 
2.23.0

[PATCH v4 10/53] KVM: PPC: Book3S HV: Don't always save PMU for guest capable of nesting

[Nicholas Piggin]

Provide a config option that controls the workaround added by commit
63279eeb7f93 ("KVM: PPC: Book3S HV: Always save guest pmu for guest
capable of nesting"). The option defaults to y for now, but is expected
to go away within a few releases.

Nested capable guests running with the earlier commit 178266389794
("KVM: PPC: Book3S HV Nested: Reflect guest PMU in-use to L0 when guest
SPRs are live") will now indicate the PMU in-use status of their guests,
which means the parent does not need to unconditionally save the PMU for
nested capable guests.

After this latest round of performance optimisations, this option costs
about 540 cycles or 10% entry/exit performance on a POWER9 nested-capable
guest.

References: 178266389794 ("KVM: PPC: Book3S HV Nested: Reflect guest PMU in-use to L0 when guest SPRs are live")
Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/kvm/Kconfig     | 15 +++++++++++++++
 arch/powerpc/kvm/book3s_hv.c | 10 ++++++++--
 2 files changed, 23 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/kvm/Kconfig b/arch/powerpc/kvm/Kconfig
index ff581d70f20c..6a58532300c5 100644
--- a/arch/powerpc/kvm/Kconfig
+++ b/arch/powerpc/kvm/Kconfig
@@ -130,6 +130,21 @@ config KVM_BOOK3S_HV_EXIT_TIMING
 
 	  If unsure, say N.
 
+config KVM_BOOK3S_HV_NESTED_PMU_WORKAROUND
+	bool "Nested L0 host workaround for L1 KVM host PMU handling bug" if EXPERT
+	depends on KVM_BOOK3S_HV_POSSIBLE
+	default !EXPERT
+	help
+	  Old nested HV capable Linux guests have a bug where they don't
+	  reflect the PMU in-use status of their L2 guest to the L0 host
+	  while the L2 PMU registers are live. This can result in loss
+          of L2 PMU register state, causing perf to not work correctly in
+	  L2 guests.
+
+	  Selecting this option for the L0 host implements a workaround for
+	  those buggy L1s which saves the L2 state, at the cost of performance
+	  in all nested-capable guest entry/exit.
+
 config KVM_BOOKE_HV
 	bool
 
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index a683ee5f420a..6e760f48bbaf 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -4047,8 +4047,14 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
 		vcpu->arch.vpa.dirty = 1;
 		save_pmu = lp->pmcregs_in_use;
 	}
-	/* Must save pmu if this guest is capable of running nested guests */
-	save_pmu |= nesting_enabled(vcpu->kvm);
+	if (IS_ENABLED(CONFIG_KVM_BOOK3S_HV_NESTED_PMU_WORKAROUND)) {
+		/*
+		 * Save pmu if this guest is capable of running nested guests.
+		 * This is option is for old L1s that do not set their
+		 * lppaca->pmcregs_in_use properly when entering their L2.
+		 */
+		save_pmu |= nesting_enabled(vcpu->kvm);
+	}
 
 	kvmhv_save_guest_pmu(vcpu, save_pmu);
 #ifdef CONFIG_PPC_PSERIES
-- 
2.23.0

[PATCH v4 11/53] powerpc/64s: Always set PMU control registers to frozen/disabled when not in use

[Nicholas Piggin]

KVM PMU management code looks for particular frozen/disabled bits in
the PMU registers so it knows whether it must clear them when coming
out of a guest or not. Setting this up helps KVM make these optimisations
without getting confused. Longer term the better approach might be to
move guest/host PMU switching to the perf subsystem.

Cc: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
Reviewed-by: Athira Jajeev <atrajeev@linux.vnet.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/kernel/cpu_setup_power.c | 4 ++--
 arch/powerpc/kernel/dt_cpu_ftrs.c     | 6 +++---
 arch/powerpc/kvm/book3s_hv.c          | 5 +++++
 3 files changed, 10 insertions(+), 5 deletions(-)

diff --git a/arch/powerpc/kernel/cpu_setup_power.c b/arch/powerpc/kernel/cpu_setup_power.c
index a29dc8326622..3dc61e203f37 100644
--- a/arch/powerpc/kernel/cpu_setup_power.c
+++ b/arch/powerpc/kernel/cpu_setup_power.c
@@ -109,7 +109,7 @@ static void init_PMU_HV_ISA207(void)
 static void init_PMU(void)
 {
 	mtspr(SPRN_MMCRA, 0);
-	mtspr(SPRN_MMCR0, 0);
+	mtspr(SPRN_MMCR0, MMCR0_FC);
 	mtspr(SPRN_MMCR1, 0);
 	mtspr(SPRN_MMCR2, 0);
 }
@@ -123,7 +123,7 @@ static void init_PMU_ISA31(void)
 {
 	mtspr(SPRN_MMCR3, 0);
 	mtspr(SPRN_MMCRA, MMCRA_BHRB_DISABLE);
-	mtspr(SPRN_MMCR0, MMCR0_PMCCEXT);
+	mtspr(SPRN_MMCR0, MMCR0_FC | MMCR0_PMCCEXT);
 }
 
 /*
diff --git a/arch/powerpc/kernel/dt_cpu_ftrs.c b/arch/powerpc/kernel/dt_cpu_ftrs.c
index de59971319ab..d2b35fb9181d 100644
--- a/arch/powerpc/kernel/dt_cpu_ftrs.c
+++ b/arch/powerpc/kernel/dt_cpu_ftrs.c
@@ -353,7 +353,7 @@ static void init_pmu_power8(void)
 	}
 
 	mtspr(SPRN_MMCRA, 0);
-	mtspr(SPRN_MMCR0, 0);
+	mtspr(SPRN_MMCR0, MMCR0_FC);
 	mtspr(SPRN_MMCR1, 0);
 	mtspr(SPRN_MMCR2, 0);
 	mtspr(SPRN_MMCRS, 0);
@@ -392,7 +392,7 @@ static void init_pmu_power9(void)
 		mtspr(SPRN_MMCRC, 0);
 
 	mtspr(SPRN_MMCRA, 0);
-	mtspr(SPRN_MMCR0, 0);
+	mtspr(SPRN_MMCR0, MMCR0_FC);
 	mtspr(SPRN_MMCR1, 0);
 	mtspr(SPRN_MMCR2, 0);
 }
@@ -428,7 +428,7 @@ static void init_pmu_power10(void)
 
 	mtspr(SPRN_MMCR3, 0);
 	mtspr(SPRN_MMCRA, MMCRA_BHRB_DISABLE);
-	mtspr(SPRN_MMCR0, MMCR0_PMCCEXT);
+	mtspr(SPRN_MMCR0, MMCR0_FC | MMCR0_PMCCEXT);
 }
 
 static int __init feat_enable_pmu_power10(struct dt_cpu_feature *f)
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 6e760f48bbaf..8bf0f6337212 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -2715,6 +2715,11 @@ static int kvmppc_core_vcpu_create_hv(struct kvm_vcpu *vcpu)
 #endif
 #endif
 	vcpu->arch.mmcr[0] = MMCR0_FC;
+	if (cpu_has_feature(CPU_FTR_ARCH_31)) {
+		vcpu->arch.mmcr[0] |= MMCR0_PMCCEXT;
+		vcpu->arch.mmcra = MMCRA_BHRB_DISABLE;
+	}
+
 	vcpu->arch.ctrl = CTRL_RUNLATCH;
 	/* default to host PVR, since we can't spoof it */
 	kvmppc_set_pvr_hv(vcpu, mfspr(SPRN_PVR));
-- 
2.23.0

[PATCH v4 12/53] powerpc/64s: Implement PMU override command line option

[Nicholas Piggin]

It can be useful in simulators (with very constrained environments)
to allow some PMCs to run from boot so they can be sampled directly
by a test harness, rather than having to run perf.

A previous change freezes counters at boot by default, so provide
a boot time option to un-freeze (plus a bit more flexibility).

Cc: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
Reviewed-by: Athira Jajeev <atrajeev@linux.vnet.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 .../admin-guide/kernel-parameters.txt         |  8 +++++
 arch/powerpc/perf/core-book3s.c               | 35 +++++++++++++++++++
 2 files changed, 43 insertions(+)

diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 9725c546a0d4..2711ddb4835a 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -4144,6 +4144,14 @@
 			Override pmtimer IOPort with a hex value.
 			e.g. pmtmr=0x508
 
+	pmu_override=	[PPC] Override the PMU.
+			This option takes over the PMU facility, so it is no
+			longer usable by perf. Setting this option starts the
+			PMU counters by setting MMCR0 to 0 (the FC bit is
+			cleared). If a number is given, then MMCR1 is set to
+			that number, otherwise (e.g., 'pmu_override=on'), MMCR1
+			remains 0.
+
 	pm_debug_messages	[SUSPEND,KNL]
 			Enable suspend/resume debug messages during boot up.
 
diff --git a/arch/powerpc/perf/core-book3s.c b/arch/powerpc/perf/core-book3s.c
index 73e62e9b179b..8d4ff93462fb 100644
--- a/arch/powerpc/perf/core-book3s.c
+++ b/arch/powerpc/perf/core-book3s.c
@@ -2419,8 +2419,24 @@ int register_power_pmu(struct power_pmu *pmu)
 }
 
 #ifdef CONFIG_PPC64
+static bool pmu_override = false;
+static unsigned long pmu_override_val;
+static void do_pmu_override(void *data)
+{
+	ppc_set_pmu_inuse(1);
+	if (pmu_override_val)
+		mtspr(SPRN_MMCR1, pmu_override_val);
+	mtspr(SPRN_MMCR0, mfspr(SPRN_MMCR0) & ~MMCR0_FC);
+}
+
 static int __init init_ppc64_pmu(void)
 {
+	if (cpu_has_feature(CPU_FTR_HVMODE) && pmu_override) {
+		pr_warn("disabling perf due to pmu_override= command line option.\n");
+		on_each_cpu(do_pmu_override, NULL, 1);
+		return 0;
+	}
+
 	/* run through all the pmu drivers one at a time */
 	if (!init_power5_pmu())
 		return 0;
@@ -2442,4 +2458,23 @@ static int __init init_ppc64_pmu(void)
 		return init_generic_compat_pmu();
 }
 early_initcall(init_ppc64_pmu);
+
+static int __init pmu_setup(char *str)
+{
+	unsigned long val;
+
+	if (!early_cpu_has_feature(CPU_FTR_HVMODE))
+		return 0;
+
+	pmu_override = true;
+
+	if (kstrtoul(str, 0, &val))
+		val = 0;
+
+	pmu_override_val = val;
+
+	return 1;
+}
+__setup("pmu_override=", pmu_setup);
+
 #endif
-- 
2.23.0

[PATCH v4 13/53] KVM: PPC: Book3S HV P9: Implement PMU save/restore in C

[Nicholas Piggin]

Implement the P9 path PMU save/restore code in C, and remove the
POWER9/10 code from the P7/8 path assembly.

Cc: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
Reviewed-by: Athira Jajeev <atrajeev@linux.vnet.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/include/asm/asm-prototypes.h |   5 -
 arch/powerpc/kvm/book3s_hv.c              | 221 +++++++++++++++++++---
 arch/powerpc/kvm/book3s_hv_interrupts.S   |  13 +-
 arch/powerpc/kvm/book3s_hv_rmhandlers.S   |  43 +----
 4 files changed, 208 insertions(+), 74 deletions(-)

diff --git a/arch/powerpc/include/asm/asm-prototypes.h b/arch/powerpc/include/asm/asm-prototypes.h
index 222823861a67..41b8a1e1144a 100644
--- a/arch/powerpc/include/asm/asm-prototypes.h
+++ b/arch/powerpc/include/asm/asm-prototypes.h
@@ -141,11 +141,6 @@ static inline void kvmppc_restore_tm_hv(struct kvm_vcpu *vcpu, u64 msr,
 					bool preserve_nv) { }
 #endif /* CONFIG_PPC_TRANSACTIONAL_MEM */
 
-void kvmhv_save_host_pmu(void);
-void kvmhv_load_host_pmu(void);
-void kvmhv_save_guest_pmu(struct kvm_vcpu *vcpu, bool pmu_in_use);
-void kvmhv_load_guest_pmu(struct kvm_vcpu *vcpu);
-
 void kvmppc_p9_enter_guest(struct kvm_vcpu *vcpu);
 
 long kvmppc_h_set_dabr(struct kvm_vcpu *vcpu, unsigned long dabr);
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 8bf0f6337212..8fdd640873a3 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -3775,6 +3775,196 @@ static noinline void kvmppc_run_core(struct kvmppc_vcore *vc)
 	trace_kvmppc_run_core(vc, 1);
 }
 
+/*
+ * Privileged (non-hypervisor) host registers to save.
+ */
+struct p9_host_os_sprs {
+	unsigned long dscr;
+	unsigned long tidr;
+	unsigned long iamr;
+	unsigned long amr;
+	unsigned long fscr;
+
+	unsigned int pmc1;
+	unsigned int pmc2;
+	unsigned int pmc3;
+	unsigned int pmc4;
+	unsigned int pmc5;
+	unsigned int pmc6;
+	unsigned long mmcr0;
+	unsigned long mmcr1;
+	unsigned long mmcr2;
+	unsigned long mmcr3;
+	unsigned long mmcra;
+	unsigned long siar;
+	unsigned long sier1;
+	unsigned long sier2;
+	unsigned long sier3;
+	unsigned long sdar;
+};
+
+static void freeze_pmu(unsigned long mmcr0, unsigned long mmcra)
+{
+	if (!(mmcr0 & MMCR0_FC))
+		goto do_freeze;
+	if (mmcra & MMCRA_SAMPLE_ENABLE)
+		goto do_freeze;
+	if (cpu_has_feature(CPU_FTR_ARCH_31)) {
+		if (!(mmcr0 & MMCR0_PMCCEXT))
+			goto do_freeze;
+		if (!(mmcra & MMCRA_BHRB_DISABLE))
+			goto do_freeze;
+	}
+	return;
+
+do_freeze:
+	mmcr0 = MMCR0_FC;
+	mmcra = 0;
+	if (cpu_has_feature(CPU_FTR_ARCH_31)) {
+		mmcr0 |= MMCR0_PMCCEXT;
+		mmcra = MMCRA_BHRB_DISABLE;
+	}
+
+	mtspr(SPRN_MMCR0, mmcr0);
+	mtspr(SPRN_MMCRA, mmcra);
+	isync();
+}
+
+static void save_p9_host_pmu(struct p9_host_os_sprs *host_os_sprs)
+{
+	if (ppc_get_pmu_inuse()) {
+		/*
+		 * It might be better to put PMU handling (at least for the
+		 * host) in the perf subsystem because it knows more about what
+		 * is being used.
+		 */
+
+		/* POWER9, POWER10 do not implement HPMC or SPMC */
+
+		host_os_sprs->mmcr0 = mfspr(SPRN_MMCR0);
+		host_os_sprs->mmcra = mfspr(SPRN_MMCRA);
+
+		freeze_pmu(host_os_sprs->mmcr0, host_os_sprs->mmcra);
+
+		host_os_sprs->pmc1 = mfspr(SPRN_PMC1);
+		host_os_sprs->pmc2 = mfspr(SPRN_PMC2);
+		host_os_sprs->pmc3 = mfspr(SPRN_PMC3);
+		host_os_sprs->pmc4 = mfspr(SPRN_PMC4);
+		host_os_sprs->pmc5 = mfspr(SPRN_PMC5);
+		host_os_sprs->pmc6 = mfspr(SPRN_PMC6);
+		host_os_sprs->mmcr1 = mfspr(SPRN_MMCR1);
+		host_os_sprs->mmcr2 = mfspr(SPRN_MMCR2);
+		host_os_sprs->sdar = mfspr(SPRN_SDAR);
+		host_os_sprs->siar = mfspr(SPRN_SIAR);
+		host_os_sprs->sier1 = mfspr(SPRN_SIER);
+
+		if (cpu_has_feature(CPU_FTR_ARCH_31)) {
+			host_os_sprs->mmcr3 = mfspr(SPRN_MMCR3);
+			host_os_sprs->sier2 = mfspr(SPRN_SIER2);
+			host_os_sprs->sier3 = mfspr(SPRN_SIER3);
+		}
+	}
+}
+
+static void load_p9_guest_pmu(struct kvm_vcpu *vcpu)
+{
+	mtspr(SPRN_PMC1, vcpu->arch.pmc[0]);
+	mtspr(SPRN_PMC2, vcpu->arch.pmc[1]);
+	mtspr(SPRN_PMC3, vcpu->arch.pmc[2]);
+	mtspr(SPRN_PMC4, vcpu->arch.pmc[3]);
+	mtspr(SPRN_PMC5, vcpu->arch.pmc[4]);
+	mtspr(SPRN_PMC6, vcpu->arch.pmc[5]);
+	mtspr(SPRN_MMCR1, vcpu->arch.mmcr[1]);
+	mtspr(SPRN_MMCR2, vcpu->arch.mmcr[2]);
+	mtspr(SPRN_SDAR, vcpu->arch.sdar);
+	mtspr(SPRN_SIAR, vcpu->arch.siar);
+	mtspr(SPRN_SIER, vcpu->arch.sier[0]);
+
+	if (cpu_has_feature(CPU_FTR_ARCH_31)) {
+		mtspr(SPRN_MMCR3, vcpu->arch.mmcr[3]);
+		mtspr(SPRN_SIER2, vcpu->arch.sier[1]);
+		mtspr(SPRN_SIER3, vcpu->arch.sier[2]);
+	}
+
+	/* Set MMCRA then MMCR0 last */
+	mtspr(SPRN_MMCRA, vcpu->arch.mmcra);
+	mtspr(SPRN_MMCR0, vcpu->arch.mmcr[0]);
+	/* No isync necessary because we're starting counters */
+}
+
+static void save_p9_guest_pmu(struct kvm_vcpu *vcpu)
+{
+	struct lppaca *lp;
+	int save_pmu = 1;
+
+	lp = vcpu->arch.vpa.pinned_addr;
+	if (lp)
+		save_pmu = lp->pmcregs_in_use;
+	if (IS_ENABLED(CONFIG_KVM_BOOK3S_HV_NESTED_PMU_WORKAROUND)) {
+		/*
+		 * Save pmu if this guest is capable of running nested guests.
+		 * This is option is for old L1s that do not set their
+		 * lppaca->pmcregs_in_use properly when entering their L2.
+		 */
+		save_pmu |= nesting_enabled(vcpu->kvm);
+	}
+
+	if (save_pmu) {
+		vcpu->arch.mmcr[0] = mfspr(SPRN_MMCR0);
+		vcpu->arch.mmcra = mfspr(SPRN_MMCRA);
+
+		freeze_pmu(vcpu->arch.mmcr[0], vcpu->arch.mmcra);
+
+		vcpu->arch.pmc[0] = mfspr(SPRN_PMC1);
+		vcpu->arch.pmc[1] = mfspr(SPRN_PMC2);
+		vcpu->arch.pmc[2] = mfspr(SPRN_PMC3);
+		vcpu->arch.pmc[3] = mfspr(SPRN_PMC4);
+		vcpu->arch.pmc[4] = mfspr(SPRN_PMC5);
+		vcpu->arch.pmc[5] = mfspr(SPRN_PMC6);
+		vcpu->arch.mmcr[1] = mfspr(SPRN_MMCR1);
+		vcpu->arch.mmcr[2] = mfspr(SPRN_MMCR2);
+		vcpu->arch.sdar = mfspr(SPRN_SDAR);
+		vcpu->arch.siar = mfspr(SPRN_SIAR);
+		vcpu->arch.sier[0] = mfspr(SPRN_SIER);
+
+		if (cpu_has_feature(CPU_FTR_ARCH_31)) {
+			vcpu->arch.mmcr[3] = mfspr(SPRN_MMCR3);
+			vcpu->arch.sier[1] = mfspr(SPRN_SIER2);
+			vcpu->arch.sier[2] = mfspr(SPRN_SIER3);
+		}
+	} else {
+		freeze_pmu(mfspr(SPRN_MMCR0), mfspr(SPRN_MMCRA));
+	}
+}
+
+static void load_p9_host_pmu(struct p9_host_os_sprs *host_os_sprs)
+{
+	if (ppc_get_pmu_inuse()) {
+		mtspr(SPRN_PMC1, host_os_sprs->pmc1);
+		mtspr(SPRN_PMC2, host_os_sprs->pmc2);
+		mtspr(SPRN_PMC3, host_os_sprs->pmc3);
+		mtspr(SPRN_PMC4, host_os_sprs->pmc4);
+		mtspr(SPRN_PMC5, host_os_sprs->pmc5);
+		mtspr(SPRN_PMC6, host_os_sprs->pmc6);
+		mtspr(SPRN_MMCR1, host_os_sprs->mmcr1);
+		mtspr(SPRN_MMCR2, host_os_sprs->mmcr2);
+		mtspr(SPRN_SDAR, host_os_sprs->sdar);
+		mtspr(SPRN_SIAR, host_os_sprs->siar);
+		mtspr(SPRN_SIER, host_os_sprs->sier1);
+
+		if (cpu_has_feature(CPU_FTR_ARCH_31)) {
+			mtspr(SPRN_MMCR3, host_os_sprs->mmcr3);
+			mtspr(SPRN_SIER2, host_os_sprs->sier2);
+			mtspr(SPRN_SIER3, host_os_sprs->sier3);
+		}
+
+		/* Set MMCRA then MMCR0 last */
+		mtspr(SPRN_MMCRA, host_os_sprs->mmcra);
+		mtspr(SPRN_MMCR0, host_os_sprs->mmcr0);
+		isync();
+	}
+}
+
 static void load_spr_state(struct kvm_vcpu *vcpu)
 {
 	mtspr(SPRN_DSCR, vcpu->arch.dscr);
@@ -3819,17 +4009,6 @@ static void store_spr_state(struct kvm_vcpu *vcpu)
 	vcpu->arch.dscr = mfspr(SPRN_DSCR);
 }
 
-/*
- * Privileged (non-hypervisor) host registers to save.
- */
-struct p9_host_os_sprs {
-	unsigned long dscr;
-	unsigned long tidr;
-	unsigned long iamr;
-	unsigned long amr;
-	unsigned long fscr;
-};
-
 static void save_p9_host_os_sprs(struct p9_host_os_sprs *host_os_sprs)
 {
 	host_os_sprs->dscr = mfspr(SPRN_DSCR);
@@ -3879,7 +4058,7 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
 	struct p9_host_os_sprs host_os_sprs;
 	s64 dec;
 	u64 tb, next_timer;
-	int trap, save_pmu;
+	int trap;
 
 	WARN_ON_ONCE(vcpu->arch.ceded);
 
@@ -3892,7 +4071,7 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
 
 	save_p9_host_os_sprs(&host_os_sprs);
 
-	kvmhv_save_host_pmu();		/* saves it to PACA kvm_hstate */
+	save_p9_host_pmu(&host_os_sprs);
 
 	kvmppc_subcore_enter_guest();
 
@@ -3922,7 +4101,7 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
 		barrier();
 	}
 #endif
-	kvmhv_load_guest_pmu(vcpu);
+	load_p9_guest_pmu(vcpu);
 
 	msr_check_and_set(MSR_FP | MSR_VEC | MSR_VSX);
 	load_fp_state(&vcpu->arch.fp);
@@ -4044,24 +4223,14 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
 	    cpu_has_feature(CPU_FTR_P9_TM_HV_ASSIST))
 		kvmppc_save_tm_hv(vcpu, vcpu->arch.shregs.msr, true);
 
-	save_pmu = 1;
 	if (vcpu->arch.vpa.pinned_addr) {
 		struct lppaca *lp = vcpu->arch.vpa.pinned_addr;
 		u32 yield_count = be32_to_cpu(lp->yield_count) + 1;
 		lp->yield_count = cpu_to_be32(yield_count);
 		vcpu->arch.vpa.dirty = 1;
-		save_pmu = lp->pmcregs_in_use;
-	}
-	if (IS_ENABLED(CONFIG_KVM_BOOK3S_HV_NESTED_PMU_WORKAROUND)) {
-		/*
-		 * Save pmu if this guest is capable of running nested guests.
-		 * This is option is for old L1s that do not set their
-		 * lppaca->pmcregs_in_use properly when entering their L2.
-		 */
-		save_pmu |= nesting_enabled(vcpu->kvm);
 	}
 
-	kvmhv_save_guest_pmu(vcpu, save_pmu);
+	save_p9_guest_pmu(vcpu);
 #ifdef CONFIG_PPC_PSERIES
 	if (kvmhv_on_pseries()) {
 		barrier();
@@ -4077,7 +4246,7 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
 
 	mtspr(SPRN_SPRG_VDSO_WRITE, local_paca->sprg_vdso);
 
-	kvmhv_load_host_pmu();
+	load_p9_host_pmu(&host_os_sprs);
 
 	kvmppc_subcore_exit_guest();
 
diff --git a/arch/powerpc/kvm/book3s_hv_interrupts.S b/arch/powerpc/kvm/book3s_hv_interrupts.S
index 4444f83cb133..59d89e4b154a 100644
--- a/arch/powerpc/kvm/book3s_hv_interrupts.S
+++ b/arch/powerpc/kvm/book3s_hv_interrupts.S
@@ -104,7 +104,10 @@ END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_207S)
 	mtlr	r0
 	blr
 
-_GLOBAL(kvmhv_save_host_pmu)
+/*
+ * void kvmhv_save_host_pmu(void)
+ */
+kvmhv_save_host_pmu:
 BEGIN_FTR_SECTION
 	/* Work around P8 PMAE bug */
 	li	r3, -1
@@ -138,14 +141,6 @@ BEGIN_FTR_SECTION
 	std	r8, HSTATE_MMCR2(r13)
 	std	r9, HSTATE_SIER(r13)
 END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S)
-BEGIN_FTR_SECTION
-	mfspr	r5, SPRN_MMCR3
-	mfspr	r6, SPRN_SIER2
-	mfspr	r7, SPRN_SIER3
-	std	r5, HSTATE_MMCR3(r13)
-	std	r6, HSTATE_SIER2(r13)
-	std	r7, HSTATE_SIER3(r13)
-END_FTR_SECTION_IFSET(CPU_FTR_ARCH_31)
 	mfspr	r3, SPRN_PMC1
 	mfspr	r5, SPRN_PMC2
 	mfspr	r6, SPRN_PMC3
diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
index c45ec4cd9d52..a454d65e6353 100644
--- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S
+++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
@@ -2776,10 +2776,11 @@ kvmppc_msr_interrupt:
 	blr
 
 /*
+ * void kvmhv_load_guest_pmu(struct kvm_vcpu *vcpu)
+ *
  * Load up guest PMU state.  R3 points to the vcpu struct.
  */
-_GLOBAL(kvmhv_load_guest_pmu)
-EXPORT_SYMBOL_GPL(kvmhv_load_guest_pmu)
+kvmhv_load_guest_pmu:
 	mr	r4, r3
 	mflr	r0
 	li	r3, 1
@@ -2813,27 +2814,17 @@ END_FTR_SECTION_IFSET(CPU_FTR_PMAO_BUG)
 	mtspr	SPRN_MMCRA, r6
 	mtspr	SPRN_SIAR, r7
 	mtspr	SPRN_SDAR, r8
-BEGIN_FTR_SECTION
-	ld      r5, VCPU_MMCR + 24(r4)
-	ld      r6, VCPU_SIER + 8(r4)
-	ld      r7, VCPU_SIER + 16(r4)
-	mtspr   SPRN_MMCR3, r5
-	mtspr   SPRN_SIER2, r6
-	mtspr   SPRN_SIER3, r7
-END_FTR_SECTION_IFSET(CPU_FTR_ARCH_31)
 BEGIN_FTR_SECTION
 	ld	r5, VCPU_MMCR + 16(r4)
 	ld	r6, VCPU_SIER(r4)
 	mtspr	SPRN_MMCR2, r5
 	mtspr	SPRN_SIER, r6
-BEGIN_FTR_SECTION_NESTED(96)
 	lwz	r7, VCPU_PMC + 24(r4)
 	lwz	r8, VCPU_PMC + 28(r4)
 	ld	r9, VCPU_MMCRS(r4)
 	mtspr	SPRN_SPMC1, r7
 	mtspr	SPRN_SPMC2, r8
 	mtspr	SPRN_MMCRS, r9
-END_FTR_SECTION_NESTED(CPU_FTR_ARCH_300, 0, 96)
 END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S)
 	mtspr	SPRN_MMCR0, r3
 	isync
@@ -2841,10 +2832,11 @@ END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S)
 	blr
 
 /*
+ * void kvmhv_load_host_pmu(void)
+ *
  * Reload host PMU state saved in the PACA by kvmhv_save_host_pmu.
  */
-_GLOBAL(kvmhv_load_host_pmu)
-EXPORT_SYMBOL_GPL(kvmhv_load_host_pmu)
+kvmhv_load_host_pmu:
 	mflr	r0
 	lbz	r4, PACA_PMCINUSE(r13) /* is the host using the PMU? */
 	cmpwi	r4, 0
@@ -2882,25 +2874,18 @@ BEGIN_FTR_SECTION
 	mtspr	SPRN_MMCR2, r8
 	mtspr	SPRN_SIER, r9
 END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S)
-BEGIN_FTR_SECTION
-	ld      r5, HSTATE_MMCR3(r13)
-	ld      r6, HSTATE_SIER2(r13)
-	ld      r7, HSTATE_SIER3(r13)
-	mtspr   SPRN_MMCR3, r5
-	mtspr   SPRN_SIER2, r6
-	mtspr   SPRN_SIER3, r7
-END_FTR_SECTION_IFSET(CPU_FTR_ARCH_31)
 	mtspr	SPRN_MMCR0, r3
 	isync
 	mtlr	r0
 23:	blr
 
 /*
+ * void kvmhv_save_guest_pmu(struct kvm_vcpu *vcpu, bool pmu_in_use)
+ *
  * Save guest PMU state into the vcpu struct.
  * r3 = vcpu, r4 = full save flag (PMU in use flag set in VPA)
  */
-_GLOBAL(kvmhv_save_guest_pmu)
-EXPORT_SYMBOL_GPL(kvmhv_save_guest_pmu)
+kvmhv_save_guest_pmu:
 	mr	r9, r3
 	mr	r8, r4
 BEGIN_FTR_SECTION
@@ -2949,14 +2934,6 @@ END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S)
 BEGIN_FTR_SECTION
 	std	r10, VCPU_MMCR + 16(r9)
 END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S)
-BEGIN_FTR_SECTION
-	mfspr   r5, SPRN_MMCR3
-	mfspr   r6, SPRN_SIER2
-	mfspr   r7, SPRN_SIER3
-	std     r5, VCPU_MMCR + 24(r9)
-	std     r6, VCPU_SIER + 8(r9)
-	std     r7, VCPU_SIER + 16(r9)
-END_FTR_SECTION_IFSET(CPU_FTR_ARCH_31)
 	std	r7, VCPU_SIAR(r9)
 	std	r8, VCPU_SDAR(r9)
 	mfspr	r3, SPRN_PMC1
@@ -2974,7 +2951,6 @@ END_FTR_SECTION_IFSET(CPU_FTR_ARCH_31)
 BEGIN_FTR_SECTION
 	mfspr	r5, SPRN_SIER
 	std	r5, VCPU_SIER(r9)
-BEGIN_FTR_SECTION_NESTED(96)
 	mfspr	r6, SPRN_SPMC1
 	mfspr	r7, SPRN_SPMC2
 	mfspr	r8, SPRN_MMCRS
@@ -2983,7 +2959,6 @@ BEGIN_FTR_SECTION_NESTED(96)
 	std	r8, VCPU_MMCRS(r9)
 	lis	r4, 0x8000
 	mtspr	SPRN_MMCRS, r4
-END_FTR_SECTION_NESTED(CPU_FTR_ARCH_300, 0, 96)
 END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S)
 22:	blr
 
-- 
2.23.0

[PATCH v4 14/53] KVM: PPC: Book3S HV P9: Factor PMU save/load into context switch functions

[Nicholas Piggin]

Rather than guest/host save/retsore functions, implement context switch
functions that take care of details like the VPA update for nested.

The reason to split these kind of helpers into explicit save/load
functions is mainly to schedule SPR access nicely, but PMU is a special
case where the load requires mtSPR (to stop counters) and other
difficulties, so there's less possibility to schedule those nicely. The
SPR accesses also have side-effects if the PMU is running, and in later
changes we keep the host PMU running as long as possible so this code
can be better profiled, which also complicates scheduling.

Reviewed-by: Athira Jajeev <atrajeev@linux.vnet.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/kvm/book3s_hv.c | 61 +++++++++++++++++-------------------
 1 file changed, 28 insertions(+), 33 deletions(-)

diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 8fdd640873a3..5ffaaf8a30b3 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -3830,7 +3830,8 @@ static void freeze_pmu(unsigned long mmcr0, unsigned long mmcra)
 	isync();
 }
 
-static void save_p9_host_pmu(struct p9_host_os_sprs *host_os_sprs)
+static void switch_pmu_to_guest(struct kvm_vcpu *vcpu,
+				struct p9_host_os_sprs *host_os_sprs)
 {
 	if (ppc_get_pmu_inuse()) {
 		/*
@@ -3864,10 +3865,21 @@ static void save_p9_host_pmu(struct p9_host_os_sprs *host_os_sprs)
 			host_os_sprs->sier3 = mfspr(SPRN_SIER3);
 		}
 	}
-}
 
-static void load_p9_guest_pmu(struct kvm_vcpu *vcpu)
-{
+#ifdef CONFIG_PPC_PSERIES
+	if (kvmhv_on_pseries()) {
+		barrier();
+		if (vcpu->arch.vpa.pinned_addr) {
+			struct lppaca *lp = vcpu->arch.vpa.pinned_addr;
+			get_lppaca()->pmcregs_in_use = lp->pmcregs_in_use;
+		} else {
+			get_lppaca()->pmcregs_in_use = 1;
+		}
+		barrier();
+	}
+#endif
+
+	/* load guest */
 	mtspr(SPRN_PMC1, vcpu->arch.pmc[0]);
 	mtspr(SPRN_PMC2, vcpu->arch.pmc[1]);
 	mtspr(SPRN_PMC3, vcpu->arch.pmc[2]);
@@ -3892,7 +3904,8 @@ static void load_p9_guest_pmu(struct kvm_vcpu *vcpu)
 	/* No isync necessary because we're starting counters */
 }
 
-static void save_p9_guest_pmu(struct kvm_vcpu *vcpu)
+static void switch_pmu_to_host(struct kvm_vcpu *vcpu,
+				struct p9_host_os_sprs *host_os_sprs)
 {
 	struct lppaca *lp;
 	int save_pmu = 1;
@@ -3935,10 +3948,15 @@ static void save_p9_guest_pmu(struct kvm_vcpu *vcpu)
 	} else {
 		freeze_pmu(mfspr(SPRN_MMCR0), mfspr(SPRN_MMCRA));
 	}
-}
 
-static void load_p9_host_pmu(struct p9_host_os_sprs *host_os_sprs)
-{
+#ifdef CONFIG_PPC_PSERIES
+	if (kvmhv_on_pseries()) {
+		barrier();
+		get_lppaca()->pmcregs_in_use = ppc_get_pmu_inuse();
+		barrier();
+	}
+#endif
+
 	if (ppc_get_pmu_inuse()) {
 		mtspr(SPRN_PMC1, host_os_sprs->pmc1);
 		mtspr(SPRN_PMC2, host_os_sprs->pmc2);
@@ -4071,8 +4089,6 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
 
 	save_p9_host_os_sprs(&host_os_sprs);
 
-	save_p9_host_pmu(&host_os_sprs);
-
 	kvmppc_subcore_enter_guest();
 
 	vc->entry_exit_map = 1;
@@ -4089,19 +4105,7 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
 	    cpu_has_feature(CPU_FTR_P9_TM_HV_ASSIST))
 		kvmppc_restore_tm_hv(vcpu, vcpu->arch.shregs.msr, true);
 
-#ifdef CONFIG_PPC_PSERIES
-	if (kvmhv_on_pseries()) {
-		barrier();
-		if (vcpu->arch.vpa.pinned_addr) {
-			struct lppaca *lp = vcpu->arch.vpa.pinned_addr;
-			get_lppaca()->pmcregs_in_use = lp->pmcregs_in_use;
-		} else {
-			get_lppaca()->pmcregs_in_use = 1;
-		}
-		barrier();
-	}
-#endif
-	load_p9_guest_pmu(vcpu);
+	switch_pmu_to_guest(vcpu, &host_os_sprs);
 
 	msr_check_and_set(MSR_FP | MSR_VEC | MSR_VSX);
 	load_fp_state(&vcpu->arch.fp);
@@ -4230,14 +4234,7 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
 		vcpu->arch.vpa.dirty = 1;
 	}
 
-	save_p9_guest_pmu(vcpu);
-#ifdef CONFIG_PPC_PSERIES
-	if (kvmhv_on_pseries()) {
-		barrier();
-		get_lppaca()->pmcregs_in_use = ppc_get_pmu_inuse();
-		barrier();
-	}
-#endif
+	switch_pmu_to_host(vcpu, &host_os_sprs);
 
 	vc->entry_exit_map = 0x101;
 	vc->in_guest = 0;
@@ -4246,8 +4243,6 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
 
 	mtspr(SPRN_SPRG_VDSO_WRITE, local_paca->sprg_vdso);
 
-	load_p9_host_pmu(&host_os_sprs);
-
 	kvmppc_subcore_exit_guest();
 
 	return trap;
-- 
2.23.0

[PATCH v4 15/53] KVM: PPC: Book3S HV P9: Demand fault PMU SPRs when marked not inuse

[Nicholas Piggin]

The pmcregs_in_use field in the guest VPA can not be trusted to reflect
what the guest is doing with PMU SPRs, so the PMU must always be managed
(stopped) when exiting the guest, and SPR values set when entering the
guest to ensure it can't cause a covert channel or otherwise cause other
guests or the host to misbehave.

So prevent guest access to the PMU with HFSCR[PM] if pmcregs_in_use is
clear, and avoid the PMU SPR access on every partition switch. Guests
that set pmcregs_in_use incorrectly or when first setting it and using
the PMU will take a hypervisor facility unavailable interrupt that will
bring in the PMU SPRs.

Reviewed-by: Athira Jajeev <atrajeev@linux.vnet.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/kvm/book3s_hv.c | 131 ++++++++++++++++++++++++++---------
 1 file changed, 98 insertions(+), 33 deletions(-)

diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 5ffaaf8a30b3..e66ce7a19ac6 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -1421,6 +1421,23 @@ static int kvmppc_emulate_doorbell_instr(struct kvm_vcpu *vcpu)
 	return RESUME_GUEST;
 }
 
+/*
+ * If the lppaca had pmcregs_in_use clear when we exited the guest, then
+ * HFSCR_PM is cleared for next entry. If the guest then tries to access
+ * the PMU SPRs, we get this facility unavailable interrupt. Putting HFSCR_PM
+ * back in the guest HFSCR will cause the next entry to load the PMU SPRs and
+ * allow the guest access to continue.
+ */
+static int kvmppc_pmu_unavailable(struct kvm_vcpu *vcpu)
+{
+	if (!(vcpu->arch.hfscr_permitted & HFSCR_PM))
+		return EMULATE_FAIL;
+
+	vcpu->arch.hfscr |= HFSCR_PM;
+
+	return RESUME_GUEST;
+}
+
 static int kvmppc_handle_exit_hv(struct kvm_vcpu *vcpu,
 				 struct task_struct *tsk)
 {
@@ -1702,16 +1719,22 @@ static int kvmppc_handle_exit_hv(struct kvm_vcpu *vcpu,
 	 * to emulate.
 	 * Otherwise, we just generate a program interrupt to the guest.
 	 */
-	case BOOK3S_INTERRUPT_H_FAC_UNAVAIL:
+	case BOOK3S_INTERRUPT_H_FAC_UNAVAIL: {
+		u64 cause = vcpu->arch.hfscr >> 56;
+
 		r = EMULATE_FAIL;
-		if (((vcpu->arch.hfscr >> 56) == FSCR_MSGP_LG) &&
-		    cpu_has_feature(CPU_FTR_ARCH_300))
-			r = kvmppc_emulate_doorbell_instr(vcpu);
+		if (cpu_has_feature(CPU_FTR_ARCH_300)) {
+			if (cause == FSCR_MSGP_LG)
+				r = kvmppc_emulate_doorbell_instr(vcpu);
+			if (cause == FSCR_PM_LG)
+				r = kvmppc_pmu_unavailable(vcpu);
+		}
 		if (r == EMULATE_FAIL) {
 			kvmppc_core_queue_program(vcpu, SRR1_PROGILL);
 			r = RESUME_GUEST;
 		}
 		break;
+	}
 
 	case BOOK3S_INTERRUPT_HV_RM_HARD:
 		r = RESUME_PASSTHROUGH;
@@ -2750,6 +2773,11 @@ static int kvmppc_core_vcpu_create_hv(struct kvm_vcpu *vcpu)
 
 	vcpu->arch.hfscr_permitted = vcpu->arch.hfscr;
 
+	/*
+	 * PM is demand-faulted so start with it clear.
+	 */
+	vcpu->arch.hfscr &= ~HFSCR_PM;
+
 	kvmppc_mmu_book3s_hv_init(vcpu);
 
 	vcpu->arch.state = KVMPPC_VCPU_NOTREADY;
@@ -3833,6 +3861,14 @@ static void freeze_pmu(unsigned long mmcr0, unsigned long mmcra)
 static void switch_pmu_to_guest(struct kvm_vcpu *vcpu,
 				struct p9_host_os_sprs *host_os_sprs)
 {
+	struct lppaca *lp;
+	int load_pmu = 1;
+
+	lp = vcpu->arch.vpa.pinned_addr;
+	if (lp)
+		load_pmu = lp->pmcregs_in_use;
+
+	/* Save host */
 	if (ppc_get_pmu_inuse()) {
 		/*
 		 * It might be better to put PMU handling (at least for the
@@ -3867,41 +3903,47 @@ static void switch_pmu_to_guest(struct kvm_vcpu *vcpu,
 	}
 
 #ifdef CONFIG_PPC_PSERIES
+	/* After saving PMU, before loading guest PMU, flip pmcregs_in_use */
 	if (kvmhv_on_pseries()) {
 		barrier();
-		if (vcpu->arch.vpa.pinned_addr) {
-			struct lppaca *lp = vcpu->arch.vpa.pinned_addr;
-			get_lppaca()->pmcregs_in_use = lp->pmcregs_in_use;
-		} else {
-			get_lppaca()->pmcregs_in_use = 1;
-		}
+		get_lppaca()->pmcregs_in_use = load_pmu;
 		barrier();
 	}
 #endif
 
-	/* load guest */
-	mtspr(SPRN_PMC1, vcpu->arch.pmc[0]);
-	mtspr(SPRN_PMC2, vcpu->arch.pmc[1]);
-	mtspr(SPRN_PMC3, vcpu->arch.pmc[2]);
-	mtspr(SPRN_PMC4, vcpu->arch.pmc[3]);
-	mtspr(SPRN_PMC5, vcpu->arch.pmc[4]);
-	mtspr(SPRN_PMC6, vcpu->arch.pmc[5]);
-	mtspr(SPRN_MMCR1, vcpu->arch.mmcr[1]);
-	mtspr(SPRN_MMCR2, vcpu->arch.mmcr[2]);
-	mtspr(SPRN_SDAR, vcpu->arch.sdar);
-	mtspr(SPRN_SIAR, vcpu->arch.siar);
-	mtspr(SPRN_SIER, vcpu->arch.sier[0]);
+	/*
+	 * Load guest. If the VPA said the PMCs are not in use but the guest
+	 * tried to access them anyway, HFSCR[PM] will be set by the HFAC
+	 * fault so we can make forward progress.
+	 */
+	if (load_pmu || (vcpu->arch.hfscr & HFSCR_PM)) {
+		mtspr(SPRN_PMC1, vcpu->arch.pmc[0]);
+		mtspr(SPRN_PMC2, vcpu->arch.pmc[1]);
+		mtspr(SPRN_PMC3, vcpu->arch.pmc[2]);
+		mtspr(SPRN_PMC4, vcpu->arch.pmc[3]);
+		mtspr(SPRN_PMC5, vcpu->arch.pmc[4]);
+		mtspr(SPRN_PMC6, vcpu->arch.pmc[5]);
+		mtspr(SPRN_MMCR1, vcpu->arch.mmcr[1]);
+		mtspr(SPRN_MMCR2, vcpu->arch.mmcr[2]);
+		mtspr(SPRN_SDAR, vcpu->arch.sdar);
+		mtspr(SPRN_SIAR, vcpu->arch.siar);
+		mtspr(SPRN_SIER, vcpu->arch.sier[0]);
+
+		if (cpu_has_feature(CPU_FTR_ARCH_31)) {
+			mtspr(SPRN_MMCR3, vcpu->arch.mmcr[3]);
+			mtspr(SPRN_SIER2, vcpu->arch.sier[1]);
+			mtspr(SPRN_SIER3, vcpu->arch.sier[2]);
+		}
 
-	if (cpu_has_feature(CPU_FTR_ARCH_31)) {
-		mtspr(SPRN_MMCR3, vcpu->arch.mmcr[3]);
-		mtspr(SPRN_SIER2, vcpu->arch.sier[1]);
-		mtspr(SPRN_SIER3, vcpu->arch.sier[2]);
-	}
+		/* Set MMCRA then MMCR0 last */
+		mtspr(SPRN_MMCRA, vcpu->arch.mmcra);
+		mtspr(SPRN_MMCR0, vcpu->arch.mmcr[0]);
+		/* No isync necessary because we're starting counters */
 
-	/* Set MMCRA then MMCR0 last */
-	mtspr(SPRN_MMCRA, vcpu->arch.mmcra);
-	mtspr(SPRN_MMCR0, vcpu->arch.mmcr[0]);
-	/* No isync necessary because we're starting counters */
+		if (!vcpu->arch.nested &&
+				(vcpu->arch.hfscr_permitted & HFSCR_PM))
+			vcpu->arch.hfscr |= HFSCR_PM;
+	}
 }
 
 static void switch_pmu_to_host(struct kvm_vcpu *vcpu,
@@ -3945,9 +3987,32 @@ static void switch_pmu_to_host(struct kvm_vcpu *vcpu,
 			vcpu->arch.sier[1] = mfspr(SPRN_SIER2);
 			vcpu->arch.sier[2] = mfspr(SPRN_SIER3);
 		}
-	} else {
+
+	} else if (vcpu->arch.hfscr & HFSCR_PM) {
+		/*
+		 * The guest accessed PMC SPRs without specifying they should
+		 * be preserved, or it cleared pmcregs_in_use after the last
+		 * access. Just ensure they are frozen.
+		 */
 		freeze_pmu(mfspr(SPRN_MMCR0), mfspr(SPRN_MMCRA));
-	}
+
+		/*
+		 * Demand-fault PMU register access in the guest.
+		 *
+		 * This is used to grab the guest's VPA pmcregs_in_use value
+		 * and reflect it into the host's VPA in the case of a nested
+		 * hypervisor.
+		 *
+		 * It also avoids having to zero-out SPRs after each guest
+		 * exit to avoid side-channels when.
+		 *
+		 * This is cleared here when we exit the guest, so later HFSCR
+		 * interrupt handling can add it back to run the guest with
+		 * PM enabled next time.
+		 */
+		if (!vcpu->arch.nested)
+			vcpu->arch.hfscr &= ~HFSCR_PM;
+	} /* otherwise the PMU should still be frozen */
 
 #ifdef CONFIG_PPC_PSERIES
 	if (kvmhv_on_pseries()) {
-- 
2.23.0

[PATCH v4 16/53] KVM: PPC: Book3S HV P9: Factor out yield_count increment

[Nicholas Piggin]

Factor duplicated code into a helper function.

Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/kvm/book3s_hv.c | 24 ++++++++++++------------
 1 file changed, 12 insertions(+), 12 deletions(-)

diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index e66ce7a19ac6..bbaf018dcb67 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -4131,6 +4131,16 @@ static inline bool hcall_is_xics(unsigned long req)
 		req == H_IPOLL || req == H_XIRR || req == H_XIRR_X;
 }
 
+static void vcpu_vpa_increment_dispatch(struct kvm_vcpu *vcpu)
+{
+	struct lppaca *lp = vcpu->arch.vpa.pinned_addr;
+	if (lp) {
+		u32 yield_count = be32_to_cpu(lp->yield_count) + 1;
+		lp->yield_count = cpu_to_be32(yield_count);
+		vcpu->arch.vpa.dirty = 1;
+	}
+}
+
 /*
  * Guest entry for POWER9 and later CPUs.
  */
@@ -4159,12 +4169,7 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
 	vc->entry_exit_map = 1;
 	vc->in_guest = 1;
 
-	if (vcpu->arch.vpa.pinned_addr) {
-		struct lppaca *lp = vcpu->arch.vpa.pinned_addr;
-		u32 yield_count = be32_to_cpu(lp->yield_count) + 1;
-		lp->yield_count = cpu_to_be32(yield_count);
-		vcpu->arch.vpa.dirty = 1;
-	}
+	vcpu_vpa_increment_dispatch(vcpu);
 
 	if (cpu_has_feature(CPU_FTR_TM) ||
 	    cpu_has_feature(CPU_FTR_P9_TM_HV_ASSIST))
@@ -4292,12 +4297,7 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
 	    cpu_has_feature(CPU_FTR_P9_TM_HV_ASSIST))
 		kvmppc_save_tm_hv(vcpu, vcpu->arch.shregs.msr, true);
 
-	if (vcpu->arch.vpa.pinned_addr) {
-		struct lppaca *lp = vcpu->arch.vpa.pinned_addr;
-		u32 yield_count = be32_to_cpu(lp->yield_count) + 1;
-		lp->yield_count = cpu_to_be32(yield_count);
-		vcpu->arch.vpa.dirty = 1;
-	}
+	vcpu_vpa_increment_dispatch(vcpu);
 
 	switch_pmu_to_host(vcpu, &host_os_sprs);
 
-- 
2.23.0

[PATCH v4 17/53] KVM: PPC: Book3S HV: CTRL SPR does not require read-modify-write

[Nicholas Piggin]

Processors that support KVM HV do not require read-modify-write of
the CTRL SPR to set/clear their thread's runlatch. Just write 1 or 0
to it.

Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/kvm/book3s_hv.c            |  2 +-
 arch/powerpc/kvm/book3s_hv_rmhandlers.S | 15 ++++++---------
 2 files changed, 7 insertions(+), 10 deletions(-)

diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index bbaf018dcb67..e4fb36871ce4 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -4071,7 +4071,7 @@ static void load_spr_state(struct kvm_vcpu *vcpu)
 	 */
 
 	if (!(vcpu->arch.ctrl & 1))
-		mtspr(SPRN_CTRLT, mfspr(SPRN_CTRLF) & ~1);
+		mtspr(SPRN_CTRLT, 0);
 }
 
 static void store_spr_state(struct kvm_vcpu *vcpu)
diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
index a454d65e6353..be79ae7afdf5 100644
--- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S
+++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
@@ -781,12 +781,11 @@ END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_207S)
 	mtspr	SPRN_AMR,r5
 	mtspr	SPRN_UAMOR,r6
 
-	/* Restore state of CTRL run bit; assume 1 on entry */
+	/* Restore state of CTRL run bit; the host currently has it set to 1 */
 	lwz	r5,VCPU_CTRL(r4)
 	andi.	r5,r5,1
 	bne	4f
-	mfspr	r6,SPRN_CTRLF
-	clrrdi	r6,r6,1
+	li	r6,0
 	mtspr	SPRN_CTRLT,r6
 4:
 	/* Secondary threads wait for primary to have done partition switch */
@@ -1209,12 +1208,12 @@ guest_bypass:
 	stw	r0, VCPU_CPU(r9)
 	stw	r0, VCPU_THREAD_CPU(r9)
 
-	/* Save guest CTRL register, set runlatch to 1 */
+	/* Save guest CTRL register, set runlatch to 1 if it was clear */
 	mfspr	r6,SPRN_CTRLF
 	stw	r6,VCPU_CTRL(r9)
 	andi.	r0,r6,1
 	bne	4f
-	ori	r6,r6,1
+	li	r6,1
 	mtspr	SPRN_CTRLT,r6
 4:
 	/*
@@ -2184,8 +2183,7 @@ END_FTR_SECTION_IFCLR(CPU_FTR_TM)
 	 * Also clear the runlatch bit before napping.
 	 */
 kvm_do_nap:
-	mfspr	r0, SPRN_CTRLF
-	clrrdi	r0, r0, 1
+	li	r0,0
 	mtspr	SPRN_CTRLT, r0
 
 	li	r0,1
@@ -2204,8 +2202,7 @@ kvm_nap_sequence:		/* desired LPCR value in r5 */
 
 	bl	isa206_idle_insn_mayloss
 
-	mfspr	r0, SPRN_CTRLF
-	ori	r0, r0, 1
+	li	r0,1
 	mtspr	SPRN_CTRLT, r0
 
 	mtspr	SPRN_SRR1, r3
-- 
2.23.0

[PATCH v4 18/53] KVM: PPC: Book3S HV P9: Move SPRG restore to restore_p9_host_os_sprs

[Nicholas Piggin]

Move the SPR update into its relevant helper function. This will
help with SPR scheduling improvements in later changes.

Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/kvm/book3s_hv.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index e4fb36871ce4..4e6a42b16998 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -4106,6 +4106,8 @@ static void save_p9_host_os_sprs(struct p9_host_os_sprs *host_os_sprs)
 static void restore_p9_host_os_sprs(struct kvm_vcpu *vcpu,
 				    struct p9_host_os_sprs *host_os_sprs)
 {
+	mtspr(SPRN_SPRG_VDSO_WRITE, local_paca->sprg_vdso);
+
 	mtspr(SPRN_PSPB, 0);
 	mtspr(SPRN_UAMOR, 0);
 
@@ -4306,8 +4308,6 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
 
 	timer_rearm_host_dec(tb);
 
-	mtspr(SPRN_SPRG_VDSO_WRITE, local_paca->sprg_vdso);
-
 	kvmppc_subcore_exit_guest();
 
 	return trap;
-- 
2.23.0

[PATCH v4 19/53] KVM: PPC: Book3S HV P9: Reduce mtmsrd instructions required to save host SPRs

[Nicholas Piggin]

This reduces the number of mtmsrd required to enable facility bits when
saving/restoring registers, by having the KVM code set all bits up front
rather than using individual facility functions that set their particular
MSR bits.

Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/include/asm/switch_to.h  |  2 +
 arch/powerpc/kernel/process.c         | 28 +++++++++++++
 arch/powerpc/kvm/book3s_hv.c          | 59 ++++++++++++++++++---------
 arch/powerpc/kvm/book3s_hv_p9_entry.c |  1 +
 4 files changed, 71 insertions(+), 19 deletions(-)

diff --git a/arch/powerpc/include/asm/switch_to.h b/arch/powerpc/include/asm/switch_to.h
index 9d1fbd8be1c7..e8013cd6b646 100644
--- a/arch/powerpc/include/asm/switch_to.h
+++ b/arch/powerpc/include/asm/switch_to.h
@@ -112,6 +112,8 @@ static inline void clear_task_ebb(struct task_struct *t)
 #endif
 }
 
+void kvmppc_save_user_regs(void);
+
 extern int set_thread_tidr(struct task_struct *t);
 
 #endif /* _ASM_POWERPC_SWITCH_TO_H */
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index 406d7ee9e322..8f841fbe16ad 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -1156,6 +1156,34 @@ static inline void save_sprs(struct thread_struct *t)
 #endif
 }
 
+#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
+void kvmppc_save_user_regs(void)
+{
+	unsigned long usermsr;
+
+	if (!current->thread.regs)
+		return;
+
+	usermsr = current->thread.regs->msr;
+
+	if (usermsr & MSR_FP)
+		save_fpu(current);
+
+	if (usermsr & MSR_VEC)
+		save_altivec(current);
+
+#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
+	if (usermsr & MSR_TM) {
+		current->thread.tm_tfhar = mfspr(SPRN_TFHAR);
+		current->thread.tm_tfiar = mfspr(SPRN_TFIAR);
+		current->thread.tm_texasr = mfspr(SPRN_TEXASR);
+		current->thread.regs->msr &= ~MSR_TM;
+	}
+#endif
+}
+EXPORT_SYMBOL_GPL(kvmppc_save_user_regs);
+#endif /* CONFIG_KVM_BOOK3S_HV_POSSIBLE */
+
 static inline void restore_sprs(struct thread_struct *old_thread,
 				struct thread_struct *new_thread)
 {
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 4e6a42b16998..541a023e25dd 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -4153,6 +4153,7 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
 	struct p9_host_os_sprs host_os_sprs;
 	s64 dec;
 	u64 tb, next_timer;
+	unsigned long msr;
 	int trap;
 
 	WARN_ON_ONCE(vcpu->arch.ceded);
@@ -4164,8 +4165,23 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
 	if (next_timer < time_limit)
 		time_limit = next_timer;
 
+	vcpu->arch.ceded = 0;
+
 	save_p9_host_os_sprs(&host_os_sprs);
 
+	/* MSR bits may have been cleared by context switch */
+	msr = 0;
+	if (IS_ENABLED(CONFIG_PPC_FPU))
+		msr |= MSR_FP;
+	if (cpu_has_feature(CPU_FTR_ALTIVEC))
+		msr |= MSR_VEC;
+	if (cpu_has_feature(CPU_FTR_VSX))
+		msr |= MSR_VSX;
+	if (cpu_has_feature(CPU_FTR_TM) ||
+	    cpu_has_feature(CPU_FTR_P9_TM_HV_ASSIST))
+		msr |= MSR_TM;
+	msr = msr_check_and_set(msr);
+
 	kvmppc_subcore_enter_guest();
 
 	vc->entry_exit_map = 1;
@@ -4174,12 +4190,13 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
 	vcpu_vpa_increment_dispatch(vcpu);
 
 	if (cpu_has_feature(CPU_FTR_TM) ||
-	    cpu_has_feature(CPU_FTR_P9_TM_HV_ASSIST))
+	    cpu_has_feature(CPU_FTR_P9_TM_HV_ASSIST)) {
 		kvmppc_restore_tm_hv(vcpu, vcpu->arch.shregs.msr, true);
+		msr = mfmsr(); /* TM restore can update msr */
+	}
 
 	switch_pmu_to_guest(vcpu, &host_os_sprs);
 
-	msr_check_and_set(MSR_FP | MSR_VEC | MSR_VSX);
 	load_fp_state(&vcpu->arch.fp);
 #ifdef CONFIG_ALTIVEC
 	load_vr_state(&vcpu->arch.vr);
@@ -4288,7 +4305,6 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
 
 	restore_p9_host_os_sprs(vcpu, &host_os_sprs);
 
-	msr_check_and_set(MSR_FP | MSR_VEC | MSR_VSX);
 	store_fp_state(&vcpu->arch.fp);
 #ifdef CONFIG_ALTIVEC
 	store_vr_state(&vcpu->arch.vr);
@@ -4851,19 +4867,24 @@ static int kvmppc_vcpu_run_hv(struct kvm_vcpu *vcpu)
 	unsigned long user_tar = 0;
 	unsigned int user_vrsave;
 	struct kvm *kvm;
+	unsigned long msr;
 
 	if (!vcpu->arch.sane) {
 		run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
 		return -EINVAL;
 	}
 
+	/* No need to go into the guest when all we'll do is come back out */
+	if (signal_pending(current)) {
+		run->exit_reason = KVM_EXIT_INTR;
+		return -EINTR;
+	}
+
+#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
 	/*
 	 * Don't allow entry with a suspended transaction, because
 	 * the guest entry/exit code will lose it.
-	 * If the guest has TM enabled, save away their TM-related SPRs
-	 * (they will get restored by the TM unavailable interrupt).
 	 */
-#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
 	if (cpu_has_feature(CPU_FTR_TM) && current->thread.regs &&
 	    (current->thread.regs->msr & MSR_TM)) {
 		if (MSR_TM_ACTIVE(current->thread.regs->msr)) {
@@ -4871,12 +4892,6 @@ static int kvmppc_vcpu_run_hv(struct kvm_vcpu *vcpu)
 			run->fail_entry.hardware_entry_failure_reason = 0;
 			return -EINVAL;
 		}
-		/* Enable TM so we can read the TM SPRs */
-		mtmsr(mfmsr() | MSR_TM);
-		current->thread.tm_tfhar = mfspr(SPRN_TFHAR);
-		current->thread.tm_tfiar = mfspr(SPRN_TFIAR);
-		current->thread.tm_texasr = mfspr(SPRN_TEXASR);
-		current->thread.regs->msr &= ~MSR_TM;
 	}
 #endif
 
@@ -4891,18 +4906,24 @@ static int kvmppc_vcpu_run_hv(struct kvm_vcpu *vcpu)
 
 	kvmppc_core_prepare_to_enter(vcpu);
 
-	/* No need to go into the guest when all we'll do is come back out */
-	if (signal_pending(current)) {
-		run->exit_reason = KVM_EXIT_INTR;
-		return -EINTR;
-	}
-
 	kvm = vcpu->kvm;
 	atomic_inc(&kvm->arch.vcpus_running);
 	/* Order vcpus_running vs. mmu_ready, see kvmppc_alloc_reset_hpt */
 	smp_mb();
 
-	flush_all_to_thread(current);
+	msr = 0;
+	if (IS_ENABLED(CONFIG_PPC_FPU))
+		msr |= MSR_FP;
+	if (cpu_has_feature(CPU_FTR_ALTIVEC))
+		msr |= MSR_VEC;
+	if (cpu_has_feature(CPU_FTR_VSX))
+		msr |= MSR_VSX;
+	if (cpu_has_feature(CPU_FTR_TM) ||
+	    cpu_has_feature(CPU_FTR_P9_TM_HV_ASSIST))
+		msr |= MSR_TM;
+	msr = msr_check_and_set(msr);
+
+	kvmppc_save_user_regs();
 
 	/* Save userspace EBB and other register values */
 	if (cpu_has_feature(CPU_FTR_ARCH_207S)) {
diff --git a/arch/powerpc/kvm/book3s_hv_p9_entry.c b/arch/powerpc/kvm/book3s_hv_p9_entry.c
index a7f63082b4e3..fb9cb34445ea 100644
--- a/arch/powerpc/kvm/book3s_hv_p9_entry.c
+++ b/arch/powerpc/kvm/book3s_hv_p9_entry.c
@@ -224,6 +224,7 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
 		vc->tb_offset_applied = vc->tb_offset;
 	}
 
+	/* Could avoid mfmsr by passing around, but probably no big deal */
 	msr = mfmsr();
 
 	host_hfscr = mfspr(SPRN_HFSCR);
-- 
2.23.0

[PATCH v4 20/53] KVM: PPC: Book3S HV P9: Improve mtmsrd scheduling by delaying MSR[EE] disable

[Nicholas Piggin]

Moving the mtmsrd after the host SPRs are saved and before the guest
SPRs start to be loaded can prevent an SPR scoreboard stall (because
the mtmsrd is L=1 type which does not cause context synchronisation.

This is also now more convenient to combined with the mtmsrd L=0
instruction to enable facilities just below, but that is not done yet.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/kvm/book3s_hv.c | 23 ++++++++++++++++++-----
 1 file changed, 18 insertions(+), 5 deletions(-)

diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 541a023e25dd..6b0689589e13 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -4169,6 +4169,18 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
 
 	save_p9_host_os_sprs(&host_os_sprs);
 
+	/*
+	 * This could be combined with MSR[RI] clearing, but that expands
+	 * the unrecoverable window. It would be better to cover unrecoverable
+	 * with KVM bad interrupt handling rather than use MSR[RI] at all.
+	 *
+	 * Much more difficult and less worthwhile to combine with IR/DR
+	 * disable.
+	 */
+	hard_irq_disable();
+	if (lazy_irq_pending())
+		return 0;
+
 	/* MSR bits may have been cleared by context switch */
 	msr = 0;
 	if (IS_ENABLED(CONFIG_PPC_FPU))
@@ -4680,6 +4692,7 @@ int kvmhv_run_single_vcpu(struct kvm_vcpu *vcpu, u64 time_limit,
 	struct kvmppc_vcore *vc;
 	struct kvm *kvm = vcpu->kvm;
 	struct kvm_nested_guest *nested = vcpu->arch.nested;
+	unsigned long flags;
 
 	trace_kvmppc_run_vcpu_enter(vcpu);
 
@@ -4723,11 +4736,11 @@ int kvmhv_run_single_vcpu(struct kvm_vcpu *vcpu, u64 time_limit,
 	if (kvm_is_radix(kvm))
 		kvmppc_prepare_radix_vcpu(vcpu, pcpu);
 
-	local_irq_disable();
-	hard_irq_disable();
+	/* flags save not required, but irq_pmu has no disable/enable API */
+	powerpc_local_irq_pmu_save(flags);
 	if (signal_pending(current))
 		goto sigpend;
-	if (lazy_irq_pending() || need_resched() || !kvm->arch.mmu_ready)
+	if (need_resched() || !kvm->arch.mmu_ready)
 		goto out;
 
 	if (!nested) {
@@ -4795,7 +4808,7 @@ int kvmhv_run_single_vcpu(struct kvm_vcpu *vcpu, u64 time_limit,
 	}
 	vtime_account_guest_exit();
 
-	local_irq_enable();
+	powerpc_local_irq_pmu_restore(flags);
 
 	cpumask_clear_cpu(pcpu, &kvm->arch.cpu_in_guest);
 
@@ -4853,7 +4866,7 @@ int kvmhv_run_single_vcpu(struct kvm_vcpu *vcpu, u64 time_limit,
 	run->exit_reason = KVM_EXIT_INTR;
 	vcpu->arch.ret = -EINTR;
  out:
-	local_irq_enable();
+	powerpc_local_irq_pmu_restore(flags);
 	preempt_enable();
 	goto done;
 }
-- 
2.23.0

[PATCH v4 21/53] KVM: PPC: Book3S HV P9: Add kvmppc_stop_thread to match kvmppc_start_thread

[Nicholas Piggin]

Small cleanup makes it a bit easier to match up entry and exit
operations.

Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/kvm/book3s_hv.c | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 6b0689589e13..d326e6a20abd 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -3070,6 +3070,13 @@ static void kvmppc_start_thread(struct kvm_vcpu *vcpu, struct kvmppc_vcore *vc)
 		kvmppc_ipi_thread(cpu);
 }
 
+/* Old path does this in asm */
+static void kvmppc_stop_thread(struct kvm_vcpu *vcpu)
+{
+	vcpu->cpu = -1;
+	vcpu->arch.thread_cpu = -1;
+}
+
 static void kvmppc_wait_for_nap(int n_threads)
 {
 	int cpu = smp_processor_id();
@@ -4310,8 +4317,6 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
 		dec = (s32) dec;
 	tb = mftb();
 	vcpu->arch.dec_expires = dec + tb;
-	vcpu->cpu = -1;
-	vcpu->arch.thread_cpu = -1;
 
 	store_spr_state(vcpu);
 
@@ -4808,6 +4813,8 @@ int kvmhv_run_single_vcpu(struct kvm_vcpu *vcpu, u64 time_limit,
 	}
 	vtime_account_guest_exit();
 
+	kvmppc_stop_thread(vcpu);
+
 	powerpc_local_irq_pmu_restore(flags);
 
 	cpumask_clear_cpu(pcpu, &kvm->arch.cpu_in_guest);
-- 
2.23.0

[PATCH v4 22/53] KVM: PPC: Book3S HV: Change dec_expires to be relative to guest timebase

[Nicholas Piggin]

Change dec_expires to be relative to the guest timebase, and allow
it to be moved into low level P9 guest entry functions, to improve
SPR access scheduling.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/include/asm/kvm_book3s.h   |  6 +++
 arch/powerpc/include/asm/kvm_host.h     |  2 +-
 arch/powerpc/kvm/book3s_hv.c            | 58 +++++++++++++------------
 arch/powerpc/kvm/book3s_hv_nested.c     |  3 ++
 arch/powerpc/kvm/book3s_hv_p9_entry.c   | 10 ++++-
 arch/powerpc/kvm/book3s_hv_rmhandlers.S | 13 ------
 6 files changed, 49 insertions(+), 43 deletions(-)

diff --git a/arch/powerpc/include/asm/kvm_book3s.h b/arch/powerpc/include/asm/kvm_book3s.h
index 3d31f2c59e43..91c9f937edcd 100644
--- a/arch/powerpc/include/asm/kvm_book3s.h
+++ b/arch/powerpc/include/asm/kvm_book3s.h
@@ -406,6 +406,12 @@ static inline ulong kvmppc_get_fault_dar(struct kvm_vcpu *vcpu)
 	return vcpu->arch.fault_dar;
 }
 
+/* Expiry time of vcpu DEC relative to host TB */
+static inline u64 kvmppc_dec_expires_host_tb(struct kvm_vcpu *vcpu)
+{
+	return vcpu->arch.dec_expires - vcpu->arch.vcore->tb_offset;
+}
+
 static inline bool is_kvmppc_resume_guest(int r)
 {
 	return (r == RESUME_GUEST || r == RESUME_GUEST_NV);
diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h
index e4d23193eba7..21ca15c3bc0b 100644
--- a/arch/powerpc/include/asm/kvm_host.h
+++ b/arch/powerpc/include/asm/kvm_host.h
@@ -741,7 +741,7 @@ struct kvm_vcpu_arch {
 
 	struct hrtimer dec_timer;
 	u64 dec_jiffies;
-	u64 dec_expires;
+	u64 dec_expires;	/* Relative to guest timebase. */
 	unsigned long pending_exceptions;
 	u8 ceded;
 	u8 prodded;
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index d326e6a20abd..bc4afec760ca 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -2261,8 +2261,7 @@ static int kvmppc_get_one_reg_hv(struct kvm_vcpu *vcpu, u64 id,
 		*val = get_reg_val(id, vcpu->arch.vcore->arch_compat);
 		break;
 	case KVM_REG_PPC_DEC_EXPIRY:
-		*val = get_reg_val(id, vcpu->arch.dec_expires +
-				   vcpu->arch.vcore->tb_offset);
+		*val = get_reg_val(id, vcpu->arch.dec_expires);
 		break;
 	case KVM_REG_PPC_ONLINE:
 		*val = get_reg_val(id, vcpu->arch.online);
@@ -2514,8 +2513,7 @@ static int kvmppc_set_one_reg_hv(struct kvm_vcpu *vcpu, u64 id,
 		r = kvmppc_set_arch_compat(vcpu, set_reg_val(id, *val));
 		break;
 	case KVM_REG_PPC_DEC_EXPIRY:
-		vcpu->arch.dec_expires = set_reg_val(id, *val) -
-			vcpu->arch.vcore->tb_offset;
+		vcpu->arch.dec_expires = set_reg_val(id, *val);
 		break;
 	case KVM_REG_PPC_ONLINE:
 		i = set_reg_val(id, *val);
@@ -2902,13 +2900,13 @@ static void kvmppc_set_timer(struct kvm_vcpu *vcpu)
 	unsigned long dec_nsec, now;
 
 	now = get_tb();
-	if (now > vcpu->arch.dec_expires) {
+	if (now > kvmppc_dec_expires_host_tb(vcpu)) {
 		/* decrementer has already gone negative */
 		kvmppc_core_queue_dec(vcpu);
 		kvmppc_core_prepare_to_enter(vcpu);
 		return;
 	}
-	dec_nsec = tb_to_ns(vcpu->arch.dec_expires - now);
+	dec_nsec = tb_to_ns(kvmppc_dec_expires_host_tb(vcpu) - now);
 	hrtimer_start(&vcpu->arch.dec_timer, dec_nsec, HRTIMER_MODE_REL);
 	vcpu->arch.timer_running = 1;
 }
@@ -3380,7 +3378,7 @@ static void post_guest_process(struct kvmppc_vcore *vc, bool is_master)
 		 */
 		spin_unlock(&vc->lock);
 		/* cancel pending dec exception if dec is positive */
-		if (now < vcpu->arch.dec_expires &&
+		if (now < kvmppc_dec_expires_host_tb(vcpu) &&
 		    kvmppc_core_pending_dec(vcpu))
 			kvmppc_core_dequeue_dec(vcpu);
 
@@ -4224,20 +4222,6 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
 
 	load_spr_state(vcpu);
 
-	/*
-	 * When setting DEC, we must always deal with irq_work_raise via NMI vs
-	 * setting DEC. The problem occurs right as we switch into guest mode
-	 * if a NMI hits and sets pending work and sets DEC, then that will
-	 * apply to the guest and not bring us back to the host.
-	 *
-	 * irq_work_raise could check a flag (or possibly LPCR[HDICE] for
-	 * example) and set HDEC to 1? That wouldn't solve the nested hv
-	 * case which needs to abort the hcall or zero the time limit.
-	 *
-	 * XXX: Another day's problem.
-	 */
-	mtspr(SPRN_DEC, vcpu->arch.dec_expires - tb);
-
 	if (kvmhv_on_pseries()) {
 		/*
 		 * We need to save and restore the guest visible part of the
@@ -4263,6 +4247,23 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
 			hvregs.vcpu_token = vcpu->vcpu_id;
 		}
 		hvregs.hdec_expiry = time_limit;
+
+		/*
+		 * When setting DEC, we must always deal with irq_work_raise
+		 * via NMI vs setting DEC. The problem occurs right as we
+		 * switch into guest mode if a NMI hits and sets pending work
+		 * and sets DEC, then that will apply to the guest and not
+		 * bring us back to the host.
+		 *
+		 * irq_work_raise could check a flag (or possibly LPCR[HDICE]
+		 * for example) and set HDEC to 1? That wouldn't solve the
+		 * nested hv case which needs to abort the hcall or zero the
+		 * time limit.
+		 *
+		 * XXX: Another day's problem.
+		 */
+		mtspr(SPRN_DEC, kvmppc_dec_expires_host_tb(vcpu) - tb);
+
 		mtspr(SPRN_DAR, vcpu->arch.shregs.dar);
 		mtspr(SPRN_DSISR, vcpu->arch.shregs.dsisr);
 		trap = plpar_hcall_norets(H_ENTER_NESTED, __pa(&hvregs),
@@ -4274,6 +4275,12 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
 		vcpu->arch.psscr = mfspr(SPRN_PSSCR_PR);
 		mtspr(SPRN_PSSCR_PR, host_psscr);
 
+		dec = mfspr(SPRN_DEC);
+		if (!(lpcr & LPCR_LD)) /* Sign extend if not using large decrementer */
+			dec = (s32) dec;
+		tb = mftb();
+		vcpu->arch.dec_expires = dec + (tb + vc->tb_offset);
+
 		/* H_CEDE has to be handled now, not later */
 		if (trap == BOOK3S_INTERRUPT_SYSCALL && !vcpu->arch.nested &&
 		    kvmppc_get_gpr(vcpu, 3) == H_CEDE) {
@@ -4281,6 +4288,7 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
 			kvmppc_set_gpr(vcpu, 3, 0);
 			trap = 0;
 		}
+
 	} else {
 		kvmppc_xive_push_vcpu(vcpu);
 		trap = kvmhv_vcpu_entry_p9(vcpu, time_limit, lpcr);
@@ -4312,12 +4320,6 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
 			vcpu->arch.slb_max = 0;
 	}
 
-	dec = mfspr(SPRN_DEC);
-	if (!(lpcr & LPCR_LD)) /* Sign extend if not using large decrementer */
-		dec = (s32) dec;
-	tb = mftb();
-	vcpu->arch.dec_expires = dec + tb;
-
 	store_spr_state(vcpu);
 
 	restore_p9_host_os_sprs(vcpu, &host_os_sprs);
@@ -4827,7 +4829,7 @@ int kvmhv_run_single_vcpu(struct kvm_vcpu *vcpu, u64 time_limit,
 	 * by L2 and the L1 decrementer is provided in hdec_expires
 	 */
 	if (kvmppc_core_pending_dec(vcpu) &&
-			((get_tb() < vcpu->arch.dec_expires) ||
+			((get_tb() < kvmppc_dec_expires_host_tb(vcpu)) ||
 			 (trap == BOOK3S_INTERRUPT_SYSCALL &&
 			  kvmppc_get_gpr(vcpu, 3) == H_ENTER_NESTED)))
 		kvmppc_core_dequeue_dec(vcpu);
diff --git a/arch/powerpc/kvm/book3s_hv_nested.c b/arch/powerpc/kvm/book3s_hv_nested.c
index ed8a2c9f5629..7bed0b91245e 100644
--- a/arch/powerpc/kvm/book3s_hv_nested.c
+++ b/arch/powerpc/kvm/book3s_hv_nested.c
@@ -358,6 +358,7 @@ long kvmhv_enter_nested_guest(struct kvm_vcpu *vcpu)
 	/* convert TB values/offsets to host (L0) values */
 	hdec_exp = l2_hv.hdec_expiry - vc->tb_offset;
 	vc->tb_offset += l2_hv.tb_offset;
+	vcpu->arch.dec_expires += l2_hv.tb_offset;
 
 	/* set L1 state to L2 state */
 	vcpu->arch.nested = l2;
@@ -399,6 +400,8 @@ long kvmhv_enter_nested_guest(struct kvm_vcpu *vcpu)
 	if (l2_regs.msr & MSR_TS_MASK)
 		vcpu->arch.shregs.msr |= MSR_TS_S;
 	vc->tb_offset = saved_l1_hv.tb_offset;
+	/* XXX: is this always the same delta as saved_l1_hv.tb_offset? */
+	vcpu->arch.dec_expires -= l2_hv.tb_offset;
 	restore_hv_regs(vcpu, &saved_l1_hv);
 	vcpu->arch.purr += delta_purr;
 	vcpu->arch.spurr += delta_spurr;
diff --git a/arch/powerpc/kvm/book3s_hv_p9_entry.c b/arch/powerpc/kvm/book3s_hv_p9_entry.c
index fb9cb34445ea..814b0dfd590f 100644
--- a/arch/powerpc/kvm/book3s_hv_p9_entry.c
+++ b/arch/powerpc/kvm/book3s_hv_p9_entry.c
@@ -188,7 +188,7 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
 	struct kvm *kvm = vcpu->kvm;
 	struct kvm_nested_guest *nested = vcpu->arch.nested;
 	struct kvmppc_vcore *vc = vcpu->arch.vcore;
-	s64 hdec;
+	s64 hdec, dec;
 	u64 tb, purr, spurr;
 	u64 *exsave;
 	bool ri_set;
@@ -317,6 +317,8 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
 	 */
 	mtspr(SPRN_HDEC, hdec);
 
+	mtspr(SPRN_DEC, vcpu->arch.dec_expires - tb);
+
 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
 tm_return_to_guest:
 #endif
@@ -461,6 +463,12 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
 	vcpu->arch.shregs.sprg2 = mfspr(SPRN_SPRG2);
 	vcpu->arch.shregs.sprg3 = mfspr(SPRN_SPRG3);
 
+	dec = mfspr(SPRN_DEC);
+	if (!(lpcr & LPCR_LD)) /* Sign extend if not using large decrementer */
+		dec = (s32) dec;
+	tb = mftb();
+	vcpu->arch.dec_expires = dec + tb;
+
 	/* Preserve PSSCR[FAKE_SUSPEND] until we've called kvmppc_save_tm_hv */
 	mtspr(SPRN_PSSCR, host_psscr |
 	      (local_paca->kvm_hstate.fake_suspend << PSSCR_FAKE_SUSPEND_LG));
diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
index be79ae7afdf5..3f1aeff72438 100644
--- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S
+++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
@@ -814,10 +814,6 @@ END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_207S)
 	 * Set the decrementer to the guest decrementer.
 	 */
 	ld	r8,VCPU_DEC_EXPIRES(r4)
-	/* r8 is a host timebase value here, convert to guest TB */
-	ld	r5,HSTATE_KVM_VCORE(r13)
-	ld	r6,VCORE_TB_OFFSET_APPL(r5)
-	add	r8,r8,r6
 	mftb	r7
 	subf	r3,r7,r8
 	mtspr	SPRN_DEC,r3
@@ -1192,9 +1188,6 @@ guest_bypass:
 	mftb	r6
 	extsw	r5,r5
 16:	add	r5,r5,r6
-	/* r5 is a guest timebase value here, convert to host TB */
-	ld	r4,VCORE_TB_OFFSET_APPL(r3)
-	subf	r5,r4,r5
 	std	r5,VCPU_DEC_EXPIRES(r9)
 
 	/* Increment exit count, poke other threads to exit */
@@ -2160,9 +2153,6 @@ END_FTR_SECTION_IFCLR(CPU_FTR_TM)
 	/* save expiry time of guest decrementer */
 	add	r3, r3, r5
 	ld	r4, HSTATE_KVM_VCPU(r13)
-	ld	r5, HSTATE_KVM_VCORE(r13)
-	ld	r6, VCORE_TB_OFFSET_APPL(r5)
-	subf	r3, r6, r3	/* convert to host TB value */
 	std	r3, VCPU_DEC_EXPIRES(r4)
 
 #ifdef CONFIG_KVM_BOOK3S_HV_EXIT_TIMING
@@ -2259,9 +2249,6 @@ END_FTR_SECTION_IFCLR(CPU_FTR_TM)
 
 	/* Restore guest decrementer */
 	ld	r3, VCPU_DEC_EXPIRES(r4)
-	ld	r5, HSTATE_KVM_VCORE(r13)
-	ld	r6, VCORE_TB_OFFSET_APPL(r5)
-	add	r3, r3, r6	/* convert host TB to guest TB value */
 	mftb	r7
 	subf	r3, r7, r3
 	mtspr	SPRN_DEC, r3
-- 
2.23.0

[PATCH v4 23/53] KVM: PPC: Book3S HV P9: Move TB updates

[Nicholas Piggin]

Move the TB updates between saving and loading guest and host SPRs,
to improve scheduling by keeping issue-NTC operations together as
much as possible.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/kvm/book3s_hv_p9_entry.c | 36 +++++++++++++--------------
 1 file changed, 18 insertions(+), 18 deletions(-)

diff --git a/arch/powerpc/kvm/book3s_hv_p9_entry.c b/arch/powerpc/kvm/book3s_hv_p9_entry.c
index 814b0dfd590f..e7793bb806eb 100644
--- a/arch/powerpc/kvm/book3s_hv_p9_entry.c
+++ b/arch/powerpc/kvm/book3s_hv_p9_entry.c
@@ -215,15 +215,6 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
 
 	vcpu->arch.ceded = 0;
 
-	if (vc->tb_offset) {
-		u64 new_tb = tb + vc->tb_offset;
-		mtspr(SPRN_TBU40, new_tb);
-		tb = mftb();
-		if ((tb & 0xffffff) < (new_tb & 0xffffff))
-			mtspr(SPRN_TBU40, new_tb + 0x1000000);
-		vc->tb_offset_applied = vc->tb_offset;
-	}
-
 	/* Could avoid mfmsr by passing around, but probably no big deal */
 	msr = mfmsr();
 
@@ -238,6 +229,15 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
 		host_dawrx1 = mfspr(SPRN_DAWRX1);
 	}
 
+	if (vc->tb_offset) {
+		u64 new_tb = tb + vc->tb_offset;
+		mtspr(SPRN_TBU40, new_tb);
+		tb = mftb();
+		if ((tb & 0xffffff) < (new_tb & 0xffffff))
+			mtspr(SPRN_TBU40, new_tb + 0x1000000);
+		vc->tb_offset_applied = vc->tb_offset;
+	}
+
 	if (vc->pcr)
 		mtspr(SPRN_PCR, vc->pcr | PCR_MASK);
 	mtspr(SPRN_DPDES, vc->dpdes);
@@ -469,6 +469,15 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
 	tb = mftb();
 	vcpu->arch.dec_expires = dec + tb;
 
+	if (vc->tb_offset_applied) {
+		u64 new_tb = tb - vc->tb_offset_applied;
+		mtspr(SPRN_TBU40, new_tb);
+		tb = mftb();
+		if ((tb & 0xffffff) < (new_tb & 0xffffff))
+			mtspr(SPRN_TBU40, new_tb + 0x1000000);
+		vc->tb_offset_applied = 0;
+	}
+
 	/* Preserve PSSCR[FAKE_SUSPEND] until we've called kvmppc_save_tm_hv */
 	mtspr(SPRN_PSSCR, host_psscr |
 	      (local_paca->kvm_hstate.fake_suspend << PSSCR_FAKE_SUSPEND_LG));
@@ -503,15 +512,6 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
 	if (vc->pcr)
 		mtspr(SPRN_PCR, PCR_MASK);
 
-	if (vc->tb_offset_applied) {
-		u64 new_tb = mftb() - vc->tb_offset_applied;
-		mtspr(SPRN_TBU40, new_tb);
-		tb = mftb();
-		if ((tb & 0xffffff) < (new_tb & 0xffffff))
-			mtspr(SPRN_TBU40, new_tb + 0x1000000);
-		vc->tb_offset_applied = 0;
-	}
-
 	/* HDEC must be at least as large as DEC, so decrementer_max fits */
 	mtspr(SPRN_HDEC, decrementer_max);
 
-- 
2.23.0

[PATCH v4 24/53] KVM: PPC: Book3S HV P9: Optimise timebase reads

[Nicholas Piggin]

Reduce the number of mfTB executed by passing the current timebase
around entry and exit code rather than read it multiple times.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/include/asm/kvm_book3s_64.h |  2 +-
 arch/powerpc/kvm/book3s_hv.c             | 88 +++++++++++++-----------
 arch/powerpc/kvm/book3s_hv_p9_entry.c    | 33 +++++----
 3 files changed, 65 insertions(+), 58 deletions(-)

diff --git a/arch/powerpc/include/asm/kvm_book3s_64.h b/arch/powerpc/include/asm/kvm_book3s_64.h
index fff391b9b97b..0a319ed9c2fd 100644
--- a/arch/powerpc/include/asm/kvm_book3s_64.h
+++ b/arch/powerpc/include/asm/kvm_book3s_64.h
@@ -154,7 +154,7 @@ static inline bool kvmhv_vcpu_is_radix(struct kvm_vcpu *vcpu)
 	return radix;
 }
 
-int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpcr);
+int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpcr, u64 *tb);
 
 #define KVM_DEFAULT_HPT_ORDER	24	/* 16MB HPT by default */
 #endif
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index bc4afec760ca..3a9447f75a9e 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -276,22 +276,22 @@ static void kvmppc_fast_vcpu_kick_hv(struct kvm_vcpu *vcpu)
  * they should never fail.)
  */
 
-static void kvmppc_core_start_stolen(struct kvmppc_vcore *vc)
+static void kvmppc_core_start_stolen(struct kvmppc_vcore *vc, u64 tb)
 {
 	unsigned long flags;
 
 	spin_lock_irqsave(&vc->stoltb_lock, flags);
-	vc->preempt_tb = mftb();
+	vc->preempt_tb = tb;
 	spin_unlock_irqrestore(&vc->stoltb_lock, flags);
 }
 
-static void kvmppc_core_end_stolen(struct kvmppc_vcore *vc)
+static void kvmppc_core_end_stolen(struct kvmppc_vcore *vc, u64 tb)
 {
 	unsigned long flags;
 
 	spin_lock_irqsave(&vc->stoltb_lock, flags);
 	if (vc->preempt_tb != TB_NIL) {
-		vc->stolen_tb += mftb() - vc->preempt_tb;
+		vc->stolen_tb += tb - vc->preempt_tb;
 		vc->preempt_tb = TB_NIL;
 	}
 	spin_unlock_irqrestore(&vc->stoltb_lock, flags);
@@ -301,6 +301,7 @@ static void kvmppc_core_vcpu_load_hv(struct kvm_vcpu *vcpu, int cpu)
 {
 	struct kvmppc_vcore *vc = vcpu->arch.vcore;
 	unsigned long flags;
+	u64 now = mftb();
 
 	/*
 	 * We can test vc->runner without taking the vcore lock,
@@ -309,12 +310,12 @@ static void kvmppc_core_vcpu_load_hv(struct kvm_vcpu *vcpu, int cpu)
 	 * ever sets it to NULL.
 	 */
 	if (vc->runner == vcpu && vc->vcore_state >= VCORE_SLEEPING)
-		kvmppc_core_end_stolen(vc);
+		kvmppc_core_end_stolen(vc, now);
 
 	spin_lock_irqsave(&vcpu->arch.tbacct_lock, flags);
 	if (vcpu->arch.state == KVMPPC_VCPU_BUSY_IN_HOST &&
 	    vcpu->arch.busy_preempt != TB_NIL) {
-		vcpu->arch.busy_stolen += mftb() - vcpu->arch.busy_preempt;
+		vcpu->arch.busy_stolen += now - vcpu->arch.busy_preempt;
 		vcpu->arch.busy_preempt = TB_NIL;
 	}
 	spin_unlock_irqrestore(&vcpu->arch.tbacct_lock, flags);
@@ -324,13 +325,14 @@ static void kvmppc_core_vcpu_put_hv(struct kvm_vcpu *vcpu)
 {
 	struct kvmppc_vcore *vc = vcpu->arch.vcore;
 	unsigned long flags;
+	u64 now = mftb();
 
 	if (vc->runner == vcpu && vc->vcore_state >= VCORE_SLEEPING)
-		kvmppc_core_start_stolen(vc);
+		kvmppc_core_start_stolen(vc, now);
 
 	spin_lock_irqsave(&vcpu->arch.tbacct_lock, flags);
 	if (vcpu->arch.state == KVMPPC_VCPU_BUSY_IN_HOST)
-		vcpu->arch.busy_preempt = mftb();
+		vcpu->arch.busy_preempt = now;
 	spin_unlock_irqrestore(&vcpu->arch.tbacct_lock, flags);
 }
 
@@ -685,7 +687,7 @@ static u64 vcore_stolen_time(struct kvmppc_vcore *vc, u64 now)
 }
 
 static void kvmppc_create_dtl_entry(struct kvm_vcpu *vcpu,
-				    struct kvmppc_vcore *vc)
+				    struct kvmppc_vcore *vc, u64 tb)
 {
 	struct dtl_entry *dt;
 	struct lppaca *vpa;
@@ -696,7 +698,7 @@ static void kvmppc_create_dtl_entry(struct kvm_vcpu *vcpu,
 
 	dt = vcpu->arch.dtl_ptr;
 	vpa = vcpu->arch.vpa.pinned_addr;
-	now = mftb();
+	now = tb;
 	core_stolen = vcore_stolen_time(vc, now);
 	stolen = core_stolen - vcpu->arch.stolen_logged;
 	vcpu->arch.stolen_logged = core_stolen;
@@ -2914,14 +2916,14 @@ static void kvmppc_set_timer(struct kvm_vcpu *vcpu)
 extern int __kvmppc_vcore_entry(void);
 
 static void kvmppc_remove_runnable(struct kvmppc_vcore *vc,
-				   struct kvm_vcpu *vcpu)
+				   struct kvm_vcpu *vcpu, u64 tb)
 {
 	u64 now;
 
 	if (vcpu->arch.state != KVMPPC_VCPU_RUNNABLE)
 		return;
 	spin_lock_irq(&vcpu->arch.tbacct_lock);
-	now = mftb();
+	now = tb;
 	vcpu->arch.busy_stolen += vcore_stolen_time(vc, now) -
 		vcpu->arch.stolen_logged;
 	vcpu->arch.busy_preempt = now;
@@ -3172,14 +3174,14 @@ static void kvmppc_vcore_preempt(struct kvmppc_vcore *vc)
 	}
 
 	/* Start accumulating stolen time */
-	kvmppc_core_start_stolen(vc);
+	kvmppc_core_start_stolen(vc, mftb());
 }
 
 static void kvmppc_vcore_end_preempt(struct kvmppc_vcore *vc)
 {
 	struct preempted_vcore_list *lp;
 
-	kvmppc_core_end_stolen(vc);
+	kvmppc_core_end_stolen(vc, mftb());
 	if (!list_empty(&vc->preempt_list)) {
 		lp = &per_cpu(preempted_vcores, vc->pcpu);
 		spin_lock(&lp->lock);
@@ -3306,7 +3308,7 @@ static void prepare_threads(struct kvmppc_vcore *vc)
 			vcpu->arch.ret = RESUME_GUEST;
 		else
 			continue;
-		kvmppc_remove_runnable(vc, vcpu);
+		kvmppc_remove_runnable(vc, vcpu, mftb());
 		wake_up(&vcpu->arch.cpu_run);
 	}
 }
@@ -3325,7 +3327,7 @@ static void collect_piggybacks(struct core_info *cip, int target_threads)
 			list_del_init(&pvc->preempt_list);
 			if (pvc->runner == NULL) {
 				pvc->vcore_state = VCORE_INACTIVE;
-				kvmppc_core_end_stolen(pvc);
+				kvmppc_core_end_stolen(pvc, mftb());
 			}
 			spin_unlock(&pvc->lock);
 			continue;
@@ -3334,7 +3336,7 @@ static void collect_piggybacks(struct core_info *cip, int target_threads)
 			spin_unlock(&pvc->lock);
 			continue;
 		}
-		kvmppc_core_end_stolen(pvc);
+		kvmppc_core_end_stolen(pvc, mftb());
 		pvc->vcore_state = VCORE_PIGGYBACK;
 		if (cip->total_threads >= target_threads)
 			break;
@@ -3401,7 +3403,7 @@ static void post_guest_process(struct kvmppc_vcore *vc, bool is_master)
 			else
 				++still_running;
 		} else {
-			kvmppc_remove_runnable(vc, vcpu);
+			kvmppc_remove_runnable(vc, vcpu, mftb());
 			wake_up(&vcpu->arch.cpu_run);
 		}
 	}
@@ -3410,7 +3412,7 @@ static void post_guest_process(struct kvmppc_vcore *vc, bool is_master)
 			kvmppc_vcore_preempt(vc);
 		} else if (vc->runner) {
 			vc->vcore_state = VCORE_PREEMPT;
-			kvmppc_core_start_stolen(vc);
+			kvmppc_core_start_stolen(vc, mftb());
 		} else {
 			vc->vcore_state = VCORE_INACTIVE;
 		}
@@ -3541,7 +3543,7 @@ static noinline void kvmppc_run_core(struct kvmppc_vcore *vc)
 	    ((vc->num_threads > threads_per_subcore) || !on_primary_thread())) {
 		for_each_runnable_thread(i, vcpu, vc) {
 			vcpu->arch.ret = -EBUSY;
-			kvmppc_remove_runnable(vc, vcpu);
+			kvmppc_remove_runnable(vc, vcpu, mftb());
 			wake_up(&vcpu->arch.cpu_run);
 		}
 		goto out;
@@ -3673,7 +3675,7 @@ static noinline void kvmppc_run_core(struct kvmppc_vcore *vc)
 		pvc->pcpu = pcpu + thr;
 		for_each_runnable_thread(i, vcpu, pvc) {
 			kvmppc_start_thread(vcpu, pvc);
-			kvmppc_create_dtl_entry(vcpu, pvc);
+			kvmppc_create_dtl_entry(vcpu, pvc, mftb());
 			trace_kvm_guest_enter(vcpu);
 			if (!vcpu->arch.ptid)
 				thr0_done = true;
@@ -4152,20 +4154,17 @@ static void vcpu_vpa_increment_dispatch(struct kvm_vcpu *vcpu)
  * Guest entry for POWER9 and later CPUs.
  */
 static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
-			 unsigned long lpcr)
+			 unsigned long lpcr, u64 *tb)
 {
 	struct kvmppc_vcore *vc = vcpu->arch.vcore;
 	struct p9_host_os_sprs host_os_sprs;
 	s64 dec;
-	u64 tb, next_timer;
+	u64 next_timer;
 	unsigned long msr;
 	int trap;
 
-	WARN_ON_ONCE(vcpu->arch.ceded);
-
-	tb = mftb();
 	next_timer = timer_get_next_tb();
-	if (tb >= next_timer)
+	if (*tb >= next_timer)
 		return BOOK3S_INTERRUPT_HV_DECREMENTER;
 	if (next_timer < time_limit)
 		time_limit = next_timer;
@@ -4262,7 +4261,7 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
 		 *
 		 * XXX: Another day's problem.
 		 */
-		mtspr(SPRN_DEC, kvmppc_dec_expires_host_tb(vcpu) - tb);
+		mtspr(SPRN_DEC, kvmppc_dec_expires_host_tb(vcpu) - *tb);
 
 		mtspr(SPRN_DAR, vcpu->arch.shregs.dar);
 		mtspr(SPRN_DSISR, vcpu->arch.shregs.dsisr);
@@ -4278,8 +4277,8 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
 		dec = mfspr(SPRN_DEC);
 		if (!(lpcr & LPCR_LD)) /* Sign extend if not using large decrementer */
 			dec = (s32) dec;
-		tb = mftb();
-		vcpu->arch.dec_expires = dec + (tb + vc->tb_offset);
+		*tb = mftb();
+		vcpu->arch.dec_expires = dec + (*tb + vc->tb_offset);
 
 		/* H_CEDE has to be handled now, not later */
 		if (trap == BOOK3S_INTERRUPT_SYSCALL && !vcpu->arch.nested &&
@@ -4291,7 +4290,7 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
 
 	} else {
 		kvmppc_xive_push_vcpu(vcpu);
-		trap = kvmhv_vcpu_entry_p9(vcpu, time_limit, lpcr);
+		trap = kvmhv_vcpu_entry_p9(vcpu, time_limit, lpcr, tb);
 		if (trap == BOOK3S_INTERRUPT_SYSCALL && !vcpu->arch.nested &&
 		    !(vcpu->arch.shregs.msr & MSR_PR)) {
 			unsigned long req = kvmppc_get_gpr(vcpu, 3);
@@ -4322,6 +4321,8 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
 
 	store_spr_state(vcpu);
 
+	timer_rearm_host_dec(*tb);
+
 	restore_p9_host_os_sprs(vcpu, &host_os_sprs);
 
 	store_fp_state(&vcpu->arch.fp);
@@ -4341,8 +4342,6 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
 	vc->entry_exit_map = 0x101;
 	vc->in_guest = 0;
 
-	timer_rearm_host_dec(tb);
-
 	kvmppc_subcore_exit_guest();
 
 	return trap;
@@ -4596,7 +4595,7 @@ static int kvmppc_run_vcpu(struct kvm_vcpu *vcpu)
 		if ((vc->vcore_state == VCORE_PIGGYBACK ||
 		     vc->vcore_state == VCORE_RUNNING) &&
 			   !VCORE_IS_EXITING(vc)) {
-			kvmppc_create_dtl_entry(vcpu, vc);
+			kvmppc_create_dtl_entry(vcpu, vc, mftb());
 			kvmppc_start_thread(vcpu, vc);
 			trace_kvm_guest_enter(vcpu);
 		} else if (vc->vcore_state == VCORE_SLEEPING) {
@@ -4631,7 +4630,7 @@ static int kvmppc_run_vcpu(struct kvm_vcpu *vcpu)
 		for_each_runnable_thread(i, v, vc) {
 			kvmppc_core_prepare_to_enter(v);
 			if (signal_pending(v->arch.run_task)) {
-				kvmppc_remove_runnable(vc, v);
+				kvmppc_remove_runnable(vc, v, mftb());
 				v->stat.signal_exits++;
 				v->run->exit_reason = KVM_EXIT_INTR;
 				v->arch.ret = -EINTR;
@@ -4672,7 +4671,7 @@ static int kvmppc_run_vcpu(struct kvm_vcpu *vcpu)
 		kvmppc_vcore_end_preempt(vc);
 
 	if (vcpu->arch.state == KVMPPC_VCPU_RUNNABLE) {
-		kvmppc_remove_runnable(vc, vcpu);
+		kvmppc_remove_runnable(vc, vcpu, mftb());
 		vcpu->stat.signal_exits++;
 		run->exit_reason = KVM_EXIT_INTR;
 		vcpu->arch.ret = -EINTR;
@@ -4700,6 +4699,7 @@ int kvmhv_run_single_vcpu(struct kvm_vcpu *vcpu, u64 time_limit,
 	struct kvm *kvm = vcpu->kvm;
 	struct kvm_nested_guest *nested = vcpu->arch.nested;
 	unsigned long flags;
+	u64 tb;
 
 	trace_kvmppc_run_vcpu_enter(vcpu);
 
@@ -4710,7 +4710,6 @@ int kvmhv_run_single_vcpu(struct kvm_vcpu *vcpu, u64 time_limit,
 	vc = vcpu->arch.vcore;
 	vcpu->arch.ceded = 0;
 	vcpu->arch.run_task = current;
-	vcpu->arch.stolen_logged = vcore_stolen_time(vc, mftb());
 	vcpu->arch.state = KVMPPC_VCPU_RUNNABLE;
 	vcpu->arch.busy_preempt = TB_NIL;
 	vcpu->arch.last_inst = KVM_INST_FETCH_FAILED;
@@ -4735,7 +4734,6 @@ int kvmhv_run_single_vcpu(struct kvm_vcpu *vcpu, u64 time_limit,
 	kvmppc_update_vpas(vcpu);
 
 	init_vcore_to_run(vc);
-	vc->preempt_tb = TB_NIL;
 
 	preempt_disable();
 	pcpu = smp_processor_id();
@@ -4745,6 +4743,7 @@ int kvmhv_run_single_vcpu(struct kvm_vcpu *vcpu, u64 time_limit,
 
 	/* flags save not required, but irq_pmu has no disable/enable API */
 	powerpc_local_irq_pmu_save(flags);
+
 	if (signal_pending(current))
 		goto sigpend;
 	if (need_resched() || !kvm->arch.mmu_ready)
@@ -4767,12 +4766,17 @@ int kvmhv_run_single_vcpu(struct kvm_vcpu *vcpu, u64 time_limit,
 		goto out;
 	}
 
+	tb = mftb();
+
+	vcpu->arch.stolen_logged = vcore_stolen_time(vc, tb);
+	vc->preempt_tb = TB_NIL;
+
 	kvmppc_clear_host_core(pcpu);
 
 	local_paca->kvm_hstate.napping = 0;
 	local_paca->kvm_hstate.kvm_split_mode = NULL;
 	kvmppc_start_thread(vcpu, vc);
-	kvmppc_create_dtl_entry(vcpu, vc);
+	kvmppc_create_dtl_entry(vcpu, vc, tb);
 	trace_kvm_guest_enter(vcpu);
 
 	vc->vcore_state = VCORE_RUNNING;
@@ -4787,7 +4791,7 @@ int kvmhv_run_single_vcpu(struct kvm_vcpu *vcpu, u64 time_limit,
 	/* Tell lockdep that we're about to enable interrupts */
 	trace_hardirqs_on();
 
-	trap = kvmhv_p9_guest_entry(vcpu, time_limit, lpcr);
+	trap = kvmhv_p9_guest_entry(vcpu, time_limit, lpcr, &tb);
 	vcpu->arch.trap = trap;
 
 	trace_hardirqs_off();
@@ -4829,7 +4833,7 @@ int kvmhv_run_single_vcpu(struct kvm_vcpu *vcpu, u64 time_limit,
 	 * by L2 and the L1 decrementer is provided in hdec_expires
 	 */
 	if (kvmppc_core_pending_dec(vcpu) &&
-			((get_tb() < kvmppc_dec_expires_host_tb(vcpu)) ||
+			((tb < kvmppc_dec_expires_host_tb(vcpu)) ||
 			 (trap == BOOK3S_INTERRUPT_SYSCALL &&
 			  kvmppc_get_gpr(vcpu, 3) == H_ENTER_NESTED)))
 		kvmppc_core_dequeue_dec(vcpu);
@@ -4865,7 +4869,7 @@ int kvmhv_run_single_vcpu(struct kvm_vcpu *vcpu, u64 time_limit,
 	trace_kvmppc_run_core(vc, 1);
 
  done:
-	kvmppc_remove_runnable(vc, vcpu);
+	kvmppc_remove_runnable(vc, vcpu, tb);
 	trace_kvmppc_run_vcpu_exit(vcpu);
 
 	return vcpu->arch.ret;
diff --git a/arch/powerpc/kvm/book3s_hv_p9_entry.c b/arch/powerpc/kvm/book3s_hv_p9_entry.c
index e7793bb806eb..2bd96d8256d1 100644
--- a/arch/powerpc/kvm/book3s_hv_p9_entry.c
+++ b/arch/powerpc/kvm/book3s_hv_p9_entry.c
@@ -183,13 +183,13 @@ static void save_clear_guest_mmu(struct kvm *kvm, struct kvm_vcpu *vcpu)
 	}
 }
 
-int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpcr)
+int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpcr, u64 *tb)
 {
 	struct kvm *kvm = vcpu->kvm;
 	struct kvm_nested_guest *nested = vcpu->arch.nested;
 	struct kvmppc_vcore *vc = vcpu->arch.vcore;
 	s64 hdec, dec;
-	u64 tb, purr, spurr;
+	u64 purr, spurr;
 	u64 *exsave;
 	bool ri_set;
 	int trap;
@@ -203,8 +203,7 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
 	unsigned long host_dawr1;
 	unsigned long host_dawrx1;
 
-	tb = mftb();
-	hdec = time_limit - tb;
+	hdec = time_limit - *tb;
 	if (hdec < 0)
 		return BOOK3S_INTERRUPT_HV_DECREMENTER;
 
@@ -230,11 +229,13 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
 	}
 
 	if (vc->tb_offset) {
-		u64 new_tb = tb + vc->tb_offset;
+		u64 new_tb = *tb + vc->tb_offset;
 		mtspr(SPRN_TBU40, new_tb);
-		tb = mftb();
-		if ((tb & 0xffffff) < (new_tb & 0xffffff))
-			mtspr(SPRN_TBU40, new_tb + 0x1000000);
+		if ((mftb() & 0xffffff) < (new_tb & 0xffffff)) {
+			new_tb += 0x1000000;
+			mtspr(SPRN_TBU40, new_tb);
+		}
+		*tb = new_tb;
 		vc->tb_offset_applied = vc->tb_offset;
 	}
 
@@ -317,7 +318,7 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
 	 */
 	mtspr(SPRN_HDEC, hdec);
 
-	mtspr(SPRN_DEC, vcpu->arch.dec_expires - tb);
+	mtspr(SPRN_DEC, vcpu->arch.dec_expires - *tb);
 
 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
 tm_return_to_guest:
@@ -466,15 +467,17 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
 	dec = mfspr(SPRN_DEC);
 	if (!(lpcr & LPCR_LD)) /* Sign extend if not using large decrementer */
 		dec = (s32) dec;
-	tb = mftb();
-	vcpu->arch.dec_expires = dec + tb;
+	*tb = mftb();
+	vcpu->arch.dec_expires = dec + *tb;
 
 	if (vc->tb_offset_applied) {
-		u64 new_tb = tb - vc->tb_offset_applied;
+		u64 new_tb = *tb - vc->tb_offset_applied;
 		mtspr(SPRN_TBU40, new_tb);
-		tb = mftb();
-		if ((tb & 0xffffff) < (new_tb & 0xffffff))
-			mtspr(SPRN_TBU40, new_tb + 0x1000000);
+		if ((mftb() & 0xffffff) < (new_tb & 0xffffff)) {
+			new_tb += 0x1000000;
+			mtspr(SPRN_TBU40, new_tb);
+		}
+		*tb = new_tb;
 		vc->tb_offset_applied = 0;
 	}
 
-- 
2.23.0

[PATCH v4 25/53] KVM: PPC: Book3S HV P9: Avoid SPR scoreboard stalls

[Nicholas Piggin]

Avoid interleaving mfSPR and mtSPR to reduce SPR scoreboard stalls.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/kvm/book3s_hv.c          |  8 ++++----
 arch/powerpc/kvm/book3s_hv_p9_entry.c | 19 +++++++++++--------
 2 files changed, 15 insertions(+), 12 deletions(-)

diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 3a9447f75a9e..75a674b5cd84 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -4321,10 +4321,6 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
 
 	store_spr_state(vcpu);
 
-	timer_rearm_host_dec(*tb);
-
-	restore_p9_host_os_sprs(vcpu, &host_os_sprs);
-
 	store_fp_state(&vcpu->arch.fp);
 #ifdef CONFIG_ALTIVEC
 	store_vr_state(&vcpu->arch.vr);
@@ -4339,6 +4335,10 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
 
 	switch_pmu_to_host(vcpu, &host_os_sprs);
 
+	timer_rearm_host_dec(*tb);
+
+	restore_p9_host_os_sprs(vcpu, &host_os_sprs);
+
 	vc->entry_exit_map = 0x101;
 	vc->in_guest = 0;
 
diff --git a/arch/powerpc/kvm/book3s_hv_p9_entry.c b/arch/powerpc/kvm/book3s_hv_p9_entry.c
index 2bd96d8256d1..bd0021cd3a67 100644
--- a/arch/powerpc/kvm/book3s_hv_p9_entry.c
+++ b/arch/powerpc/kvm/book3s_hv_p9_entry.c
@@ -228,6 +228,9 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
 		host_dawrx1 = mfspr(SPRN_DAWRX1);
 	}
 
+	local_paca->kvm_hstate.host_purr = mfspr(SPRN_PURR);
+	local_paca->kvm_hstate.host_spurr = mfspr(SPRN_SPURR);
+
 	if (vc->tb_offset) {
 		u64 new_tb = *tb + vc->tb_offset;
 		mtspr(SPRN_TBU40, new_tb);
@@ -244,8 +247,6 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
 	mtspr(SPRN_DPDES, vc->dpdes);
 	mtspr(SPRN_VTB, vc->vtb);
 
-	local_paca->kvm_hstate.host_purr = mfspr(SPRN_PURR);
-	local_paca->kvm_hstate.host_spurr = mfspr(SPRN_SPURR);
 	mtspr(SPRN_PURR, vcpu->arch.purr);
 	mtspr(SPRN_SPURR, vcpu->arch.spurr);
 
@@ -448,10 +449,8 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
 	/* Advance host PURR/SPURR by the amount used by guest */
 	purr = mfspr(SPRN_PURR);
 	spurr = mfspr(SPRN_SPURR);
-	mtspr(SPRN_PURR, local_paca->kvm_hstate.host_purr +
-	      purr - vcpu->arch.purr);
-	mtspr(SPRN_SPURR, local_paca->kvm_hstate.host_spurr +
-	      spurr - vcpu->arch.spurr);
+	local_paca->kvm_hstate.host_purr += purr - vcpu->arch.purr;
+	local_paca->kvm_hstate.host_spurr += spurr - vcpu->arch.spurr;
 	vcpu->arch.purr = purr;
 	vcpu->arch.spurr = spurr;
 
@@ -464,6 +463,9 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
 	vcpu->arch.shregs.sprg2 = mfspr(SPRN_SPRG2);
 	vcpu->arch.shregs.sprg3 = mfspr(SPRN_SPRG3);
 
+	vc->dpdes = mfspr(SPRN_DPDES);
+	vc->vtb = mfspr(SPRN_VTB);
+
 	dec = mfspr(SPRN_DEC);
 	if (!(lpcr & LPCR_LD)) /* Sign extend if not using large decrementer */
 		dec = (s32) dec;
@@ -481,6 +483,9 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
 		vc->tb_offset_applied = 0;
 	}
 
+	mtspr(SPRN_PURR, local_paca->kvm_hstate.host_purr);
+	mtspr(SPRN_SPURR, local_paca->kvm_hstate.host_spurr);
+
 	/* Preserve PSSCR[FAKE_SUSPEND] until we've called kvmppc_save_tm_hv */
 	mtspr(SPRN_PSSCR, host_psscr |
 	      (local_paca->kvm_hstate.fake_suspend << PSSCR_FAKE_SUSPEND_LG));
@@ -509,8 +514,6 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
 	if (cpu_has_feature(CPU_FTR_ARCH_31))
 		asm volatile(PPC_CP_ABORT);
 
-	vc->dpdes = mfspr(SPRN_DPDES);
-	vc->vtb = mfspr(SPRN_VTB);
 	mtspr(SPRN_DPDES, 0);
 	if (vc->pcr)
 		mtspr(SPRN_PCR, PCR_MASK);
-- 
2.23.0

[PATCH v4 26/53] KVM: PPC: Book3S HV P9: Only execute mtSPR if the value changed

[Nicholas Piggin]

Keep better track of the current SPR value in places where
they are to be loaded with a new context, to reduce expensive
mtSPR operations.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/kvm/book3s_hv.c | 51 ++++++++++++++++++++++--------------
 1 file changed, 31 insertions(+), 20 deletions(-)

diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 75a674b5cd84..5c44c4ff5d46 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -4055,20 +4055,28 @@ static void switch_pmu_to_host(struct kvm_vcpu *vcpu,
 	}
 }
 
-static void load_spr_state(struct kvm_vcpu *vcpu)
+static void load_spr_state(struct kvm_vcpu *vcpu,
+				struct p9_host_os_sprs *host_os_sprs)
 {
-	mtspr(SPRN_DSCR, vcpu->arch.dscr);
-	mtspr(SPRN_IAMR, vcpu->arch.iamr);
-	mtspr(SPRN_PSPB, vcpu->arch.pspb);
-	mtspr(SPRN_FSCR, vcpu->arch.fscr);
 	mtspr(SPRN_TAR, vcpu->arch.tar);
 	mtspr(SPRN_EBBHR, vcpu->arch.ebbhr);
 	mtspr(SPRN_EBBRR, vcpu->arch.ebbrr);
 	mtspr(SPRN_BESCR, vcpu->arch.bescr);
+
 	if (cpu_has_feature(CPU_FTR_P9_TIDR))
 		mtspr(SPRN_TIDR, vcpu->arch.tid);
-	mtspr(SPRN_AMR, vcpu->arch.amr);
-	mtspr(SPRN_UAMOR, vcpu->arch.uamor);
+	if (host_os_sprs->iamr != vcpu->arch.iamr)
+		mtspr(SPRN_IAMR, vcpu->arch.iamr);
+	if (host_os_sprs->amr != vcpu->arch.amr)
+		mtspr(SPRN_AMR, vcpu->arch.amr);
+	if (vcpu->arch.uamor != 0)
+		mtspr(SPRN_UAMOR, vcpu->arch.uamor);
+	if (host_os_sprs->fscr != vcpu->arch.fscr)
+		mtspr(SPRN_FSCR, vcpu->arch.fscr);
+	if (host_os_sprs->dscr != vcpu->arch.dscr)
+		mtspr(SPRN_DSCR, vcpu->arch.dscr);
+	if (vcpu->arch.pspb != 0)
+		mtspr(SPRN_PSPB, vcpu->arch.pspb);
 
 	/*
 	 * DAR, DSISR, and for nested HV, SPRGs must be set with MSR[RI]
@@ -4083,20 +4091,21 @@ static void load_spr_state(struct kvm_vcpu *vcpu)
 
 static void store_spr_state(struct kvm_vcpu *vcpu)
 {
-	vcpu->arch.ctrl = mfspr(SPRN_CTRLF);
-
-	vcpu->arch.iamr = mfspr(SPRN_IAMR);
-	vcpu->arch.pspb = mfspr(SPRN_PSPB);
-	vcpu->arch.fscr = mfspr(SPRN_FSCR);
 	vcpu->arch.tar = mfspr(SPRN_TAR);
 	vcpu->arch.ebbhr = mfspr(SPRN_EBBHR);
 	vcpu->arch.ebbrr = mfspr(SPRN_EBBRR);
 	vcpu->arch.bescr = mfspr(SPRN_BESCR);
+
 	if (cpu_has_feature(CPU_FTR_P9_TIDR))
 		vcpu->arch.tid = mfspr(SPRN_TIDR);
+	vcpu->arch.iamr = mfspr(SPRN_IAMR);
 	vcpu->arch.amr = mfspr(SPRN_AMR);
 	vcpu->arch.uamor = mfspr(SPRN_UAMOR);
+	vcpu->arch.fscr = mfspr(SPRN_FSCR);
 	vcpu->arch.dscr = mfspr(SPRN_DSCR);
+	vcpu->arch.pspb = mfspr(SPRN_PSPB);
+
+	vcpu->arch.ctrl = mfspr(SPRN_CTRLF);
 }
 
 static void save_p9_host_os_sprs(struct p9_host_os_sprs *host_os_sprs)
@@ -4107,6 +4116,7 @@ static void save_p9_host_os_sprs(struct p9_host_os_sprs *host_os_sprs)
 	host_os_sprs->iamr = mfspr(SPRN_IAMR);
 	host_os_sprs->amr = mfspr(SPRN_AMR);
 	host_os_sprs->fscr = mfspr(SPRN_FSCR);
+	host_os_sprs->dscr = mfspr(SPRN_DSCR);
 }
 
 /* vcpu guest regs must already be saved */
@@ -4115,19 +4125,20 @@ static void restore_p9_host_os_sprs(struct kvm_vcpu *vcpu,
 {
 	mtspr(SPRN_SPRG_VDSO_WRITE, local_paca->sprg_vdso);
 
-	mtspr(SPRN_PSPB, 0);
-	mtspr(SPRN_UAMOR, 0);
-
-	mtspr(SPRN_DSCR, host_os_sprs->dscr);
 	if (cpu_has_feature(CPU_FTR_P9_TIDR))
 		mtspr(SPRN_TIDR, host_os_sprs->tidr);
-	mtspr(SPRN_IAMR, host_os_sprs->iamr);
-
+	if (host_os_sprs->iamr != vcpu->arch.iamr)
+		mtspr(SPRN_IAMR, host_os_sprs->iamr);
+	if (vcpu->arch.uamor != 0)
+		mtspr(SPRN_UAMOR, 0);
 	if (host_os_sprs->amr != vcpu->arch.amr)
 		mtspr(SPRN_AMR, host_os_sprs->amr);
-
 	if (host_os_sprs->fscr != vcpu->arch.fscr)
 		mtspr(SPRN_FSCR, host_os_sprs->fscr);
+	if (host_os_sprs->dscr != vcpu->arch.dscr)
+		mtspr(SPRN_DSCR, host_os_sprs->dscr);
+	if (vcpu->arch.pspb != 0)
+		mtspr(SPRN_PSPB, 0);
 
 	/* Save guest CTRL register, set runlatch to 1 */
 	if (!(vcpu->arch.ctrl & 1))
@@ -4219,7 +4230,7 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
 #endif
 	mtspr(SPRN_VRSAVE, vcpu->arch.vrsave);
 
-	load_spr_state(vcpu);
+	load_spr_state(vcpu, &host_os_sprs);
 
 	if (kvmhv_on_pseries()) {
 		/*
-- 
2.23.0

[PATCH v4 27/53] KVM: PPC: Book3S HV P9: Juggle SPR switching around

[Nicholas Piggin]

This juggles SPR switching on the entry and exit sides to be more
symmetric, which makes the next refactoring patch possible with no
functional change.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/kvm/book3s_hv.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 5c44c4ff5d46..53fe41102c22 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -4222,7 +4222,7 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
 		msr = mfmsr(); /* TM restore can update msr */
 	}
 
-	switch_pmu_to_guest(vcpu, &host_os_sprs);
+	load_spr_state(vcpu, &host_os_sprs);
 
 	load_fp_state(&vcpu->arch.fp);
 #ifdef CONFIG_ALTIVEC
@@ -4230,7 +4230,7 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
 #endif
 	mtspr(SPRN_VRSAVE, vcpu->arch.vrsave);
 
-	load_spr_state(vcpu, &host_os_sprs);
+	switch_pmu_to_guest(vcpu, &host_os_sprs);
 
 	if (kvmhv_on_pseries()) {
 		/*
@@ -4330,6 +4330,8 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
 			vcpu->arch.slb_max = 0;
 	}
 
+	switch_pmu_to_host(vcpu, &host_os_sprs);
+
 	store_spr_state(vcpu);
 
 	store_fp_state(&vcpu->arch.fp);
@@ -4344,8 +4346,6 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
 
 	vcpu_vpa_increment_dispatch(vcpu);
 
-	switch_pmu_to_host(vcpu, &host_os_sprs);
-
 	timer_rearm_host_dec(*tb);
 
 	restore_p9_host_os_sprs(vcpu, &host_os_sprs);
-- 
2.23.0

[PATCH v4 28/53] KVM: PPC: Book3S HV P9: Move vcpu register save/restore into functions

[Nicholas Piggin]

This should be no functional difference but makes the caller easier
to read.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/kvm/book3s_hv.c | 65 +++++++++++++++++++++++-------------
 1 file changed, 41 insertions(+), 24 deletions(-)

diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 53fe41102c22..0eb52f2732a4 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -4108,6 +4108,44 @@ static void store_spr_state(struct kvm_vcpu *vcpu)
 	vcpu->arch.ctrl = mfspr(SPRN_CTRLF);
 }
 
+/* Returns true if current MSR and/or guest MSR may have changed */
+static bool load_vcpu_state(struct kvm_vcpu *vcpu,
+			   struct p9_host_os_sprs *host_os_sprs)
+{
+	bool ret = false;
+
+	if (cpu_has_feature(CPU_FTR_TM) ||
+	    cpu_has_feature(CPU_FTR_P9_TM_HV_ASSIST)) {
+		kvmppc_restore_tm_hv(vcpu, vcpu->arch.shregs.msr, true);
+		ret = true;
+	}
+
+	load_spr_state(vcpu, host_os_sprs);
+
+	load_fp_state(&vcpu->arch.fp);
+#ifdef CONFIG_ALTIVEC
+	load_vr_state(&vcpu->arch.vr);
+#endif
+	mtspr(SPRN_VRSAVE, vcpu->arch.vrsave);
+
+	return ret;
+}
+
+static void store_vcpu_state(struct kvm_vcpu *vcpu)
+{
+	store_spr_state(vcpu);
+
+	store_fp_state(&vcpu->arch.fp);
+#ifdef CONFIG_ALTIVEC
+	store_vr_state(&vcpu->arch.vr);
+#endif
+	vcpu->arch.vrsave = mfspr(SPRN_VRSAVE);
+
+	if (cpu_has_feature(CPU_FTR_TM) ||
+	    cpu_has_feature(CPU_FTR_P9_TM_HV_ASSIST))
+		kvmppc_save_tm_hv(vcpu, vcpu->arch.shregs.msr, true);
+}
+
 static void save_p9_host_os_sprs(struct p9_host_os_sprs *host_os_sprs)
 {
 	host_os_sprs->dscr = mfspr(SPRN_DSCR);
@@ -4216,19 +4254,8 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
 
 	vcpu_vpa_increment_dispatch(vcpu);
 
-	if (cpu_has_feature(CPU_FTR_TM) ||
-	    cpu_has_feature(CPU_FTR_P9_TM_HV_ASSIST)) {
-		kvmppc_restore_tm_hv(vcpu, vcpu->arch.shregs.msr, true);
-		msr = mfmsr(); /* TM restore can update msr */
-	}
-
-	load_spr_state(vcpu, &host_os_sprs);
-
-	load_fp_state(&vcpu->arch.fp);
-#ifdef CONFIG_ALTIVEC
-	load_vr_state(&vcpu->arch.vr);
-#endif
-	mtspr(SPRN_VRSAVE, vcpu->arch.vrsave);
+	if (unlikely(load_vcpu_state(vcpu, &host_os_sprs)))
+		msr = mfmsr(); /* MSR may have been updated */
 
 	switch_pmu_to_guest(vcpu, &host_os_sprs);
 
@@ -4332,17 +4359,7 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
 
 	switch_pmu_to_host(vcpu, &host_os_sprs);
 
-	store_spr_state(vcpu);
-
-	store_fp_state(&vcpu->arch.fp);
-#ifdef CONFIG_ALTIVEC
-	store_vr_state(&vcpu->arch.vr);
-#endif
-	vcpu->arch.vrsave = mfspr(SPRN_VRSAVE);
-
-	if (cpu_has_feature(CPU_FTR_TM) ||
-	    cpu_has_feature(CPU_FTR_P9_TM_HV_ASSIST))
-		kvmppc_save_tm_hv(vcpu, vcpu->arch.shregs.msr, true);
+	store_vcpu_state(vcpu);
 
 	vcpu_vpa_increment_dispatch(vcpu);
 
-- 
2.23.0

[PATCH v4 29/53] KVM: PPC: Book3S HV P9: Move host OS save/restore functions to built-in

[Nicholas Piggin]

Move the P9 guest/host register switching functions to the built-in
P9 entry code, and export it for nested to use as well.

This allows more flexibility in scheduling these supervisor privileged
SPR accesses with the HV privileged and PR SPR accesses in the low level
entry code.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/kvm/book3s_hv.c          | 379 +-------------------------
 arch/powerpc/kvm/book3s_hv.h          |  45 +++
 arch/powerpc/kvm/book3s_hv_p9_entry.c | 353 ++++++++++++++++++++++++
 3 files changed, 399 insertions(+), 378 deletions(-)
 create mode 100644 arch/powerpc/kvm/book3s_hv.h

diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 0eb52f2732a4..8a9d2314d67c 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -80,6 +80,7 @@
 #include <asm/plpar_wrappers.h>
 
 #include "book3s.h"
+#include "book3s_hv.h"
 
 #define CREATE_TRACE_POINTS
 #include "trace_hv.h"
@@ -127,11 +128,6 @@ static bool nested = true;
 module_param(nested, bool, S_IRUGO | S_IWUSR);
 MODULE_PARM_DESC(nested, "Enable nested virtualization (only on POWER9)");
 
-static inline bool nesting_enabled(struct kvm *kvm)
-{
-	return kvm->arch.nested_enable && kvm_is_radix(kvm);
-}
-
 static int kvmppc_hv_setup_htab_rma(struct kvm_vcpu *vcpu);
 
 /*
@@ -3810,379 +3806,6 @@ static noinline void kvmppc_run_core(struct kvmppc_vcore *vc)
 	trace_kvmppc_run_core(vc, 1);
 }
 
-/*
- * Privileged (non-hypervisor) host registers to save.
- */
-struct p9_host_os_sprs {
-	unsigned long dscr;
-	unsigned long tidr;
-	unsigned long iamr;
-	unsigned long amr;
-	unsigned long fscr;
-
-	unsigned int pmc1;
-	unsigned int pmc2;
-	unsigned int pmc3;
-	unsigned int pmc4;
-	unsigned int pmc5;
-	unsigned int pmc6;
-	unsigned long mmcr0;
-	unsigned long mmcr1;
-	unsigned long mmcr2;
-	unsigned long mmcr3;
-	unsigned long mmcra;
-	unsigned long siar;
-	unsigned long sier1;
-	unsigned long sier2;
-	unsigned long sier3;
-	unsigned long sdar;
-};
-
-static void freeze_pmu(unsigned long mmcr0, unsigned long mmcra)
-{
-	if (!(mmcr0 & MMCR0_FC))
-		goto do_freeze;
-	if (mmcra & MMCRA_SAMPLE_ENABLE)
-		goto do_freeze;
-	if (cpu_has_feature(CPU_FTR_ARCH_31)) {
-		if (!(mmcr0 & MMCR0_PMCCEXT))
-			goto do_freeze;
-		if (!(mmcra & MMCRA_BHRB_DISABLE))
-			goto do_freeze;
-	}
-	return;
-
-do_freeze:
-	mmcr0 = MMCR0_FC;
-	mmcra = 0;
-	if (cpu_has_feature(CPU_FTR_ARCH_31)) {
-		mmcr0 |= MMCR0_PMCCEXT;
-		mmcra = MMCRA_BHRB_DISABLE;
-	}
-
-	mtspr(SPRN_MMCR0, mmcr0);
-	mtspr(SPRN_MMCRA, mmcra);
-	isync();
-}
-
-static void switch_pmu_to_guest(struct kvm_vcpu *vcpu,
-				struct p9_host_os_sprs *host_os_sprs)
-{
-	struct lppaca *lp;
-	int load_pmu = 1;
-
-	lp = vcpu->arch.vpa.pinned_addr;
-	if (lp)
-		load_pmu = lp->pmcregs_in_use;
-
-	/* Save host */
-	if (ppc_get_pmu_inuse()) {
-		/*
-		 * It might be better to put PMU handling (at least for the
-		 * host) in the perf subsystem because it knows more about what
-		 * is being used.
-		 */
-
-		/* POWER9, POWER10 do not implement HPMC or SPMC */
-
-		host_os_sprs->mmcr0 = mfspr(SPRN_MMCR0);
-		host_os_sprs->mmcra = mfspr(SPRN_MMCRA);
-
-		freeze_pmu(host_os_sprs->mmcr0, host_os_sprs->mmcra);
-
-		host_os_sprs->pmc1 = mfspr(SPRN_PMC1);
-		host_os_sprs->pmc2 = mfspr(SPRN_PMC2);
-		host_os_sprs->pmc3 = mfspr(SPRN_PMC3);
-		host_os_sprs->pmc4 = mfspr(SPRN_PMC4);
-		host_os_sprs->pmc5 = mfspr(SPRN_PMC5);
-		host_os_sprs->pmc6 = mfspr(SPRN_PMC6);
-		host_os_sprs->mmcr1 = mfspr(SPRN_MMCR1);
-		host_os_sprs->mmcr2 = mfspr(SPRN_MMCR2);
-		host_os_sprs->sdar = mfspr(SPRN_SDAR);
-		host_os_sprs->siar = mfspr(SPRN_SIAR);
-		host_os_sprs->sier1 = mfspr(SPRN_SIER);
-
-		if (cpu_has_feature(CPU_FTR_ARCH_31)) {
-			host_os_sprs->mmcr3 = mfspr(SPRN_MMCR3);
-			host_os_sprs->sier2 = mfspr(SPRN_SIER2);
-			host_os_sprs->sier3 = mfspr(SPRN_SIER3);
-		}
-	}
-
-#ifdef CONFIG_PPC_PSERIES
-	/* After saving PMU, before loading guest PMU, flip pmcregs_in_use */
-	if (kvmhv_on_pseries()) {
-		barrier();
-		get_lppaca()->pmcregs_in_use = load_pmu;
-		barrier();
-	}
-#endif
-
-	/*
-	 * Load guest. If the VPA said the PMCs are not in use but the guest
-	 * tried to access them anyway, HFSCR[PM] will be set by the HFAC
-	 * fault so we can make forward progress.
-	 */
-	if (load_pmu || (vcpu->arch.hfscr & HFSCR_PM)) {
-		mtspr(SPRN_PMC1, vcpu->arch.pmc[0]);
-		mtspr(SPRN_PMC2, vcpu->arch.pmc[1]);
-		mtspr(SPRN_PMC3, vcpu->arch.pmc[2]);
-		mtspr(SPRN_PMC4, vcpu->arch.pmc[3]);
-		mtspr(SPRN_PMC5, vcpu->arch.pmc[4]);
-		mtspr(SPRN_PMC6, vcpu->arch.pmc[5]);
-		mtspr(SPRN_MMCR1, vcpu->arch.mmcr[1]);
-		mtspr(SPRN_MMCR2, vcpu->arch.mmcr[2]);
-		mtspr(SPRN_SDAR, vcpu->arch.sdar);
-		mtspr(SPRN_SIAR, vcpu->arch.siar);
-		mtspr(SPRN_SIER, vcpu->arch.sier[0]);
-
-		if (cpu_has_feature(CPU_FTR_ARCH_31)) {
-			mtspr(SPRN_MMCR3, vcpu->arch.mmcr[3]);
-			mtspr(SPRN_SIER2, vcpu->arch.sier[1]);
-			mtspr(SPRN_SIER3, vcpu->arch.sier[2]);
-		}
-
-		/* Set MMCRA then MMCR0 last */
-		mtspr(SPRN_MMCRA, vcpu->arch.mmcra);
-		mtspr(SPRN_MMCR0, vcpu->arch.mmcr[0]);
-		/* No isync necessary because we're starting counters */
-
-		if (!vcpu->arch.nested &&
-				(vcpu->arch.hfscr_permitted & HFSCR_PM))
-			vcpu->arch.hfscr |= HFSCR_PM;
-	}
-}
-
-static void switch_pmu_to_host(struct kvm_vcpu *vcpu,
-				struct p9_host_os_sprs *host_os_sprs)
-{
-	struct lppaca *lp;
-	int save_pmu = 1;
-
-	lp = vcpu->arch.vpa.pinned_addr;
-	if (lp)
-		save_pmu = lp->pmcregs_in_use;
-	if (IS_ENABLED(CONFIG_KVM_BOOK3S_HV_NESTED_PMU_WORKAROUND)) {
-		/*
-		 * Save pmu if this guest is capable of running nested guests.
-		 * This is option is for old L1s that do not set their
-		 * lppaca->pmcregs_in_use properly when entering their L2.
-		 */
-		save_pmu |= nesting_enabled(vcpu->kvm);
-	}
-
-	if (save_pmu) {
-		vcpu->arch.mmcr[0] = mfspr(SPRN_MMCR0);
-		vcpu->arch.mmcra = mfspr(SPRN_MMCRA);
-
-		freeze_pmu(vcpu->arch.mmcr[0], vcpu->arch.mmcra);
-
-		vcpu->arch.pmc[0] = mfspr(SPRN_PMC1);
-		vcpu->arch.pmc[1] = mfspr(SPRN_PMC2);
-		vcpu->arch.pmc[2] = mfspr(SPRN_PMC3);
-		vcpu->arch.pmc[3] = mfspr(SPRN_PMC4);
-		vcpu->arch.pmc[4] = mfspr(SPRN_PMC5);
-		vcpu->arch.pmc[5] = mfspr(SPRN_PMC6);
-		vcpu->arch.mmcr[1] = mfspr(SPRN_MMCR1);
-		vcpu->arch.mmcr[2] = mfspr(SPRN_MMCR2);
-		vcpu->arch.sdar = mfspr(SPRN_SDAR);
-		vcpu->arch.siar = mfspr(SPRN_SIAR);
-		vcpu->arch.sier[0] = mfspr(SPRN_SIER);
-
-		if (cpu_has_feature(CPU_FTR_ARCH_31)) {
-			vcpu->arch.mmcr[3] = mfspr(SPRN_MMCR3);
-			vcpu->arch.sier[1] = mfspr(SPRN_SIER2);
-			vcpu->arch.sier[2] = mfspr(SPRN_SIER3);
-		}
-
-	} else if (vcpu->arch.hfscr & HFSCR_PM) {
-		/*
-		 * The guest accessed PMC SPRs without specifying they should
-		 * be preserved, or it cleared pmcregs_in_use after the last
-		 * access. Just ensure they are frozen.
-		 */
-		freeze_pmu(mfspr(SPRN_MMCR0), mfspr(SPRN_MMCRA));
-
-		/*
-		 * Demand-fault PMU register access in the guest.
-		 *
-		 * This is used to grab the guest's VPA pmcregs_in_use value
-		 * and reflect it into the host's VPA in the case of a nested
-		 * hypervisor.
-		 *
-		 * It also avoids having to zero-out SPRs after each guest
-		 * exit to avoid side-channels when.
-		 *
-		 * This is cleared here when we exit the guest, so later HFSCR
-		 * interrupt handling can add it back to run the guest with
-		 * PM enabled next time.
-		 */
-		if (!vcpu->arch.nested)
-			vcpu->arch.hfscr &= ~HFSCR_PM;
-	} /* otherwise the PMU should still be frozen */
-
-#ifdef CONFIG_PPC_PSERIES
-	if (kvmhv_on_pseries()) {
-		barrier();
-		get_lppaca()->pmcregs_in_use = ppc_get_pmu_inuse();
-		barrier();
-	}
-#endif
-
-	if (ppc_get_pmu_inuse()) {
-		mtspr(SPRN_PMC1, host_os_sprs->pmc1);
-		mtspr(SPRN_PMC2, host_os_sprs->pmc2);
-		mtspr(SPRN_PMC3, host_os_sprs->pmc3);
-		mtspr(SPRN_PMC4, host_os_sprs->pmc4);
-		mtspr(SPRN_PMC5, host_os_sprs->pmc5);
-		mtspr(SPRN_PMC6, host_os_sprs->pmc6);
-		mtspr(SPRN_MMCR1, host_os_sprs->mmcr1);
-		mtspr(SPRN_MMCR2, host_os_sprs->mmcr2);
-		mtspr(SPRN_SDAR, host_os_sprs->sdar);
-		mtspr(SPRN_SIAR, host_os_sprs->siar);
-		mtspr(SPRN_SIER, host_os_sprs->sier1);
-
-		if (cpu_has_feature(CPU_FTR_ARCH_31)) {
-			mtspr(SPRN_MMCR3, host_os_sprs->mmcr3);
-			mtspr(SPRN_SIER2, host_os_sprs->sier2);
-			mtspr(SPRN_SIER3, host_os_sprs->sier3);
-		}
-
-		/* Set MMCRA then MMCR0 last */
-		mtspr(SPRN_MMCRA, host_os_sprs->mmcra);
-		mtspr(SPRN_MMCR0, host_os_sprs->mmcr0);
-		isync();
-	}
-}
-
-static void load_spr_state(struct kvm_vcpu *vcpu,
-				struct p9_host_os_sprs *host_os_sprs)
-{
-	mtspr(SPRN_TAR, vcpu->arch.tar);
-	mtspr(SPRN_EBBHR, vcpu->arch.ebbhr);
-	mtspr(SPRN_EBBRR, vcpu->arch.ebbrr);
-	mtspr(SPRN_BESCR, vcpu->arch.bescr);
-
-	if (cpu_has_feature(CPU_FTR_P9_TIDR))
-		mtspr(SPRN_TIDR, vcpu->arch.tid);
-	if (host_os_sprs->iamr != vcpu->arch.iamr)
-		mtspr(SPRN_IAMR, vcpu->arch.iamr);
-	if (host_os_sprs->amr != vcpu->arch.amr)
-		mtspr(SPRN_AMR, vcpu->arch.amr);
-	if (vcpu->arch.uamor != 0)
-		mtspr(SPRN_UAMOR, vcpu->arch.uamor);
-	if (host_os_sprs->fscr != vcpu->arch.fscr)
-		mtspr(SPRN_FSCR, vcpu->arch.fscr);
-	if (host_os_sprs->dscr != vcpu->arch.dscr)
-		mtspr(SPRN_DSCR, vcpu->arch.dscr);
-	if (vcpu->arch.pspb != 0)
-		mtspr(SPRN_PSPB, vcpu->arch.pspb);
-
-	/*
-	 * DAR, DSISR, and for nested HV, SPRGs must be set with MSR[RI]
-	 * clear (or hstate set appropriately to catch those registers
-	 * being clobbered if we take a MCE or SRESET), so those are done
-	 * later.
-	 */
-
-	if (!(vcpu->arch.ctrl & 1))
-		mtspr(SPRN_CTRLT, 0);
-}
-
-static void store_spr_state(struct kvm_vcpu *vcpu)
-{
-	vcpu->arch.tar = mfspr(SPRN_TAR);
-	vcpu->arch.ebbhr = mfspr(SPRN_EBBHR);
-	vcpu->arch.ebbrr = mfspr(SPRN_EBBRR);
-	vcpu->arch.bescr = mfspr(SPRN_BESCR);
-
-	if (cpu_has_feature(CPU_FTR_P9_TIDR))
-		vcpu->arch.tid = mfspr(SPRN_TIDR);
-	vcpu->arch.iamr = mfspr(SPRN_IAMR);
-	vcpu->arch.amr = mfspr(SPRN_AMR);
-	vcpu->arch.uamor = mfspr(SPRN_UAMOR);
-	vcpu->arch.fscr = mfspr(SPRN_FSCR);
-	vcpu->arch.dscr = mfspr(SPRN_DSCR);
-	vcpu->arch.pspb = mfspr(SPRN_PSPB);
-
-	vcpu->arch.ctrl = mfspr(SPRN_CTRLF);
-}
-
-/* Returns true if current MSR and/or guest MSR may have changed */
-static bool load_vcpu_state(struct kvm_vcpu *vcpu,
-			   struct p9_host_os_sprs *host_os_sprs)
-{
-	bool ret = false;
-
-	if (cpu_has_feature(CPU_FTR_TM) ||
-	    cpu_has_feature(CPU_FTR_P9_TM_HV_ASSIST)) {
-		kvmppc_restore_tm_hv(vcpu, vcpu->arch.shregs.msr, true);
-		ret = true;
-	}
-
-	load_spr_state(vcpu, host_os_sprs);
-
-	load_fp_state(&vcpu->arch.fp);
-#ifdef CONFIG_ALTIVEC
-	load_vr_state(&vcpu->arch.vr);
-#endif
-	mtspr(SPRN_VRSAVE, vcpu->arch.vrsave);
-
-	return ret;
-}
-
-static void store_vcpu_state(struct kvm_vcpu *vcpu)
-{
-	store_spr_state(vcpu);
-
-	store_fp_state(&vcpu->arch.fp);
-#ifdef CONFIG_ALTIVEC
-	store_vr_state(&vcpu->arch.vr);
-#endif
-	vcpu->arch.vrsave = mfspr(SPRN_VRSAVE);
-
-	if (cpu_has_feature(CPU_FTR_TM) ||
-	    cpu_has_feature(CPU_FTR_P9_TM_HV_ASSIST))
-		kvmppc_save_tm_hv(vcpu, vcpu->arch.shregs.msr, true);
-}
-
-static void save_p9_host_os_sprs(struct p9_host_os_sprs *host_os_sprs)
-{
-	host_os_sprs->dscr = mfspr(SPRN_DSCR);
-	if (cpu_has_feature(CPU_FTR_P9_TIDR))
-		host_os_sprs->tidr = mfspr(SPRN_TIDR);
-	host_os_sprs->iamr = mfspr(SPRN_IAMR);
-	host_os_sprs->amr = mfspr(SPRN_AMR);
-	host_os_sprs->fscr = mfspr(SPRN_FSCR);
-	host_os_sprs->dscr = mfspr(SPRN_DSCR);
-}
-
-/* vcpu guest regs must already be saved */
-static void restore_p9_host_os_sprs(struct kvm_vcpu *vcpu,
-				    struct p9_host_os_sprs *host_os_sprs)
-{
-	mtspr(SPRN_SPRG_VDSO_WRITE, local_paca->sprg_vdso);
-
-	if (cpu_has_feature(CPU_FTR_P9_TIDR))
-		mtspr(SPRN_TIDR, host_os_sprs->tidr);
-	if (host_os_sprs->iamr != vcpu->arch.iamr)
-		mtspr(SPRN_IAMR, host_os_sprs->iamr);
-	if (vcpu->arch.uamor != 0)
-		mtspr(SPRN_UAMOR, 0);
-	if (host_os_sprs->amr != vcpu->arch.amr)
-		mtspr(SPRN_AMR, host_os_sprs->amr);
-	if (host_os_sprs->fscr != vcpu->arch.fscr)
-		mtspr(SPRN_FSCR, host_os_sprs->fscr);
-	if (host_os_sprs->dscr != vcpu->arch.dscr)
-		mtspr(SPRN_DSCR, host_os_sprs->dscr);
-	if (vcpu->arch.pspb != 0)
-		mtspr(SPRN_PSPB, 0);
-
-	/* Save guest CTRL register, set runlatch to 1 */
-	if (!(vcpu->arch.ctrl & 1))
-		mtspr(SPRN_CTRLT, 1);
-}
-
 static inline bool hcall_is_xics(unsigned long req)
 {
 	return req == H_EOI || req == H_CPPR || req == H_IPI ||
diff --git a/arch/powerpc/kvm/book3s_hv.h b/arch/powerpc/kvm/book3s_hv.h
new file mode 100644
index 000000000000..d7485b9e9762
--- /dev/null
+++ b/arch/powerpc/kvm/book3s_hv.h
@@ -0,0 +1,45 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+/*
+ * Privileged (non-hypervisor) host registers to save.
+ */
+struct p9_host_os_sprs {
+	unsigned long dscr;
+	unsigned long tidr;
+	unsigned long iamr;
+	unsigned long amr;
+	unsigned long fscr;
+
+	unsigned int pmc1;
+	unsigned int pmc2;
+	unsigned int pmc3;
+	unsigned int pmc4;
+	unsigned int pmc5;
+	unsigned int pmc6;
+	unsigned long mmcr0;
+	unsigned long mmcr1;
+	unsigned long mmcr2;
+	unsigned long mmcr3;
+	unsigned long mmcra;
+	unsigned long siar;
+	unsigned long sier1;
+	unsigned long sier2;
+	unsigned long sier3;
+	unsigned long sdar;
+};
+
+static inline bool nesting_enabled(struct kvm *kvm)
+{
+	return kvm->arch.nested_enable && kvm_is_radix(kvm);
+}
+
+bool load_vcpu_state(struct kvm_vcpu *vcpu,
+			   struct p9_host_os_sprs *host_os_sprs);
+void store_vcpu_state(struct kvm_vcpu *vcpu);
+void save_p9_host_os_sprs(struct p9_host_os_sprs *host_os_sprs);
+void restore_p9_host_os_sprs(struct kvm_vcpu *vcpu,
+				    struct p9_host_os_sprs *host_os_sprs);
+void switch_pmu_to_guest(struct kvm_vcpu *vcpu,
+			    struct p9_host_os_sprs *host_os_sprs);
+void switch_pmu_to_host(struct kvm_vcpu *vcpu,
+			    struct p9_host_os_sprs *host_os_sprs);
diff --git a/arch/powerpc/kvm/book3s_hv_p9_entry.c b/arch/powerpc/kvm/book3s_hv_p9_entry.c
index bd0021cd3a67..784ff5429ebc 100644
--- a/arch/powerpc/kvm/book3s_hv_p9_entry.c
+++ b/arch/powerpc/kvm/book3s_hv_p9_entry.c
@@ -4,8 +4,361 @@
 #include <asm/asm-prototypes.h>
 #include <asm/dbell.h>
 #include <asm/kvm_ppc.h>
+#include <asm/pmc.h>
 #include <asm/ppc-opcode.h>
 
+#include "book3s_hv.h"
+
+static void freeze_pmu(unsigned long mmcr0, unsigned long mmcra)
+{
+	if (!(mmcr0 & MMCR0_FC))
+		goto do_freeze;
+	if (mmcra & MMCRA_SAMPLE_ENABLE)
+		goto do_freeze;
+	if (cpu_has_feature(CPU_FTR_ARCH_31)) {
+		if (!(mmcr0 & MMCR0_PMCCEXT))
+			goto do_freeze;
+		if (!(mmcra & MMCRA_BHRB_DISABLE))
+			goto do_freeze;
+	}
+	return;
+
+do_freeze:
+	mmcr0 = MMCR0_FC;
+	mmcra = 0;
+	if (cpu_has_feature(CPU_FTR_ARCH_31)) {
+		mmcr0 |= MMCR0_PMCCEXT;
+		mmcra = MMCRA_BHRB_DISABLE;
+	}
+
+	mtspr(SPRN_MMCR0, mmcr0);
+	mtspr(SPRN_MMCRA, mmcra);
+	isync();
+}
+
+void switch_pmu_to_guest(struct kvm_vcpu *vcpu,
+			 struct p9_host_os_sprs *host_os_sprs)
+{
+	struct lppaca *lp;
+	int load_pmu = 1;
+
+	lp = vcpu->arch.vpa.pinned_addr;
+	if (lp)
+		load_pmu = lp->pmcregs_in_use;
+
+	/* Save host */
+	if (ppc_get_pmu_inuse()) {
+		/*
+		 * It might be better to put PMU handling (at least for the
+		 * host) in the perf subsystem because it knows more about what
+		 * is being used.
+		 */
+
+		/* POWER9, POWER10 do not implement HPMC or SPMC */
+
+		host_os_sprs->mmcr0 = mfspr(SPRN_MMCR0);
+		host_os_sprs->mmcra = mfspr(SPRN_MMCRA);
+
+		freeze_pmu(host_os_sprs->mmcr0, host_os_sprs->mmcra);
+
+		host_os_sprs->pmc1 = mfspr(SPRN_PMC1);
+		host_os_sprs->pmc2 = mfspr(SPRN_PMC2);
+		host_os_sprs->pmc3 = mfspr(SPRN_PMC3);
+		host_os_sprs->pmc4 = mfspr(SPRN_PMC4);
+		host_os_sprs->pmc5 = mfspr(SPRN_PMC5);
+		host_os_sprs->pmc6 = mfspr(SPRN_PMC6);
+		host_os_sprs->mmcr1 = mfspr(SPRN_MMCR1);
+		host_os_sprs->mmcr2 = mfspr(SPRN_MMCR2);
+		host_os_sprs->sdar = mfspr(SPRN_SDAR);
+		host_os_sprs->siar = mfspr(SPRN_SIAR);
+		host_os_sprs->sier1 = mfspr(SPRN_SIER);
+
+		if (cpu_has_feature(CPU_FTR_ARCH_31)) {
+			host_os_sprs->mmcr3 = mfspr(SPRN_MMCR3);
+			host_os_sprs->sier2 = mfspr(SPRN_SIER2);
+			host_os_sprs->sier3 = mfspr(SPRN_SIER3);
+		}
+	}
+
+#ifdef CONFIG_PPC_PSERIES
+	/* After saving PMU, before loading guest PMU, flip pmcregs_in_use */
+	if (kvmhv_on_pseries()) {
+		barrier();
+		get_lppaca()->pmcregs_in_use = load_pmu;
+		barrier();
+	}
+#endif
+
+	/*
+	 * Load guest. If the VPA said the PMCs are not in use but the guest
+	 * tried to access them anyway, HFSCR[PM] will be set by the HFAC
+	 * fault so we can make forward progress.
+	 */
+	if (load_pmu || (vcpu->arch.hfscr & HFSCR_PM)) {
+		mtspr(SPRN_PMC1, vcpu->arch.pmc[0]);
+		mtspr(SPRN_PMC2, vcpu->arch.pmc[1]);
+		mtspr(SPRN_PMC3, vcpu->arch.pmc[2]);
+		mtspr(SPRN_PMC4, vcpu->arch.pmc[3]);
+		mtspr(SPRN_PMC5, vcpu->arch.pmc[4]);
+		mtspr(SPRN_PMC6, vcpu->arch.pmc[5]);
+		mtspr(SPRN_MMCR1, vcpu->arch.mmcr[1]);
+		mtspr(SPRN_MMCR2, vcpu->arch.mmcr[2]);
+		mtspr(SPRN_SDAR, vcpu->arch.sdar);
+		mtspr(SPRN_SIAR, vcpu->arch.siar);
+		mtspr(SPRN_SIER, vcpu->arch.sier[0]);
+
+		if (cpu_has_feature(CPU_FTR_ARCH_31)) {
+			mtspr(SPRN_MMCR3, vcpu->arch.mmcr[3]);
+			mtspr(SPRN_SIER2, vcpu->arch.sier[1]);
+			mtspr(SPRN_SIER3, vcpu->arch.sier[2]);
+		}
+
+		/* Set MMCRA then MMCR0 last */
+		mtspr(SPRN_MMCRA, vcpu->arch.mmcra);
+		mtspr(SPRN_MMCR0, vcpu->arch.mmcr[0]);
+		/* No isync necessary because we're starting counters */
+
+		if (!vcpu->arch.nested &&
+				(vcpu->arch.hfscr_permitted & HFSCR_PM))
+			vcpu->arch.hfscr |= HFSCR_PM;
+	}
+}
+EXPORT_SYMBOL_GPL(switch_pmu_to_guest);
+
+void switch_pmu_to_host(struct kvm_vcpu *vcpu,
+			struct p9_host_os_sprs *host_os_sprs)
+{
+	struct lppaca *lp;
+	int save_pmu = 1;
+
+	lp = vcpu->arch.vpa.pinned_addr;
+	if (lp)
+		save_pmu = lp->pmcregs_in_use;
+	if (IS_ENABLED(CONFIG_KVM_BOOK3S_HV_NESTED_PMU_WORKAROUND)) {
+		/*
+		 * Save pmu if this guest is capable of running nested guests.
+		 * This is option is for old L1s that do not set their
+		 * lppaca->pmcregs_in_use properly when entering their L2.
+		 */
+		save_pmu |= nesting_enabled(vcpu->kvm);
+	}
+
+	if (save_pmu) {
+		vcpu->arch.mmcr[0] = mfspr(SPRN_MMCR0);
+		vcpu->arch.mmcra = mfspr(SPRN_MMCRA);
+
+		freeze_pmu(vcpu->arch.mmcr[0], vcpu->arch.mmcra);
+
+		vcpu->arch.pmc[0] = mfspr(SPRN_PMC1);
+		vcpu->arch.pmc[1] = mfspr(SPRN_PMC2);
+		vcpu->arch.pmc[2] = mfspr(SPRN_PMC3);
+		vcpu->arch.pmc[3] = mfspr(SPRN_PMC4);
+		vcpu->arch.pmc[4] = mfspr(SPRN_PMC5);
+		vcpu->arch.pmc[5] = mfspr(SPRN_PMC6);
+		vcpu->arch.mmcr[1] = mfspr(SPRN_MMCR1);
+		vcpu->arch.mmcr[2] = mfspr(SPRN_MMCR2);
+		vcpu->arch.sdar = mfspr(SPRN_SDAR);
+		vcpu->arch.siar = mfspr(SPRN_SIAR);
+		vcpu->arch.sier[0] = mfspr(SPRN_SIER);
+
+		if (cpu_has_feature(CPU_FTR_ARCH_31)) {
+			vcpu->arch.mmcr[3] = mfspr(SPRN_MMCR3);
+			vcpu->arch.sier[1] = mfspr(SPRN_SIER2);
+			vcpu->arch.sier[2] = mfspr(SPRN_SIER3);
+		}
+
+	} else if (vcpu->arch.hfscr & HFSCR_PM) {
+		/*
+		 * The guest accessed PMC SPRs without specifying they should
+		 * be preserved, or it cleared pmcregs_in_use after the last
+		 * access. Just ensure they are frozen.
+		 */
+		freeze_pmu(mfspr(SPRN_MMCR0), mfspr(SPRN_MMCRA));
+
+		/*
+		 * Demand-fault PMU register access in the guest.
+		 *
+		 * This is used to grab the guest's VPA pmcregs_in_use value
+		 * and reflect it into the host's VPA in the case of a nested
+		 * hypervisor.
+		 *
+		 * It also avoids having to zero-out SPRs after each guest
+		 * exit to avoid side-channels when.
+		 *
+		 * This is cleared here when we exit the guest, so later HFSCR
+		 * interrupt handling can add it back to run the guest with
+		 * PM enabled next time.
+		 */
+		if (!vcpu->arch.nested)
+			vcpu->arch.hfscr &= ~HFSCR_PM;
+	} /* otherwise the PMU should still be frozen */
+
+#ifdef CONFIG_PPC_PSERIES
+	if (kvmhv_on_pseries()) {
+		barrier();
+		get_lppaca()->pmcregs_in_use = ppc_get_pmu_inuse();
+		barrier();
+	}
+#endif
+
+	if (ppc_get_pmu_inuse()) {
+		mtspr(SPRN_PMC1, host_os_sprs->pmc1);
+		mtspr(SPRN_PMC2, host_os_sprs->pmc2);
+		mtspr(SPRN_PMC3, host_os_sprs->pmc3);
+		mtspr(SPRN_PMC4, host_os_sprs->pmc4);
+		mtspr(SPRN_PMC5, host_os_sprs->pmc5);
+		mtspr(SPRN_PMC6, host_os_sprs->pmc6);
+		mtspr(SPRN_MMCR1, host_os_sprs->mmcr1);
+		mtspr(SPRN_MMCR2, host_os_sprs->mmcr2);
+		mtspr(SPRN_SDAR, host_os_sprs->sdar);
+		mtspr(SPRN_SIAR, host_os_sprs->siar);
+		mtspr(SPRN_SIER, host_os_sprs->sier1);
+
+		if (cpu_has_feature(CPU_FTR_ARCH_31)) {
+			mtspr(SPRN_MMCR3, host_os_sprs->mmcr3);
+			mtspr(SPRN_SIER2, host_os_sprs->sier2);
+			mtspr(SPRN_SIER3, host_os_sprs->sier3);
+		}
+
+		/* Set MMCRA then MMCR0 last */
+		mtspr(SPRN_MMCRA, host_os_sprs->mmcra);
+		mtspr(SPRN_MMCR0, host_os_sprs->mmcr0);
+		isync();
+	}
+}
+EXPORT_SYMBOL_GPL(switch_pmu_to_host);
+
+static void load_spr_state(struct kvm_vcpu *vcpu,
+				struct p9_host_os_sprs *host_os_sprs)
+{
+	mtspr(SPRN_TAR, vcpu->arch.tar);
+	mtspr(SPRN_EBBHR, vcpu->arch.ebbhr);
+	mtspr(SPRN_EBBRR, vcpu->arch.ebbrr);
+	mtspr(SPRN_BESCR, vcpu->arch.bescr);
+
+	if (cpu_has_feature(CPU_FTR_P9_TIDR))
+		mtspr(SPRN_TIDR, vcpu->arch.tid);
+	if (host_os_sprs->iamr != vcpu->arch.iamr)
+		mtspr(SPRN_IAMR, vcpu->arch.iamr);
+	if (host_os_sprs->amr != vcpu->arch.amr)
+		mtspr(SPRN_AMR, vcpu->arch.amr);
+	if (vcpu->arch.uamor != 0)
+		mtspr(SPRN_UAMOR, vcpu->arch.uamor);
+	if (host_os_sprs->fscr != vcpu->arch.fscr)
+		mtspr(SPRN_FSCR, vcpu->arch.fscr);
+	if (host_os_sprs->dscr != vcpu->arch.dscr)
+		mtspr(SPRN_DSCR, vcpu->arch.dscr);
+	if (vcpu->arch.pspb != 0)
+		mtspr(SPRN_PSPB, vcpu->arch.pspb);
+
+	/*
+	 * DAR, DSISR, and for nested HV, SPRGs must be set with MSR[RI]
+	 * clear (or hstate set appropriately to catch those registers
+	 * being clobbered if we take a MCE or SRESET), so those are done
+	 * later.
+	 */
+
+	if (!(vcpu->arch.ctrl & 1))
+		mtspr(SPRN_CTRLT, 0);
+}
+
+static void store_spr_state(struct kvm_vcpu *vcpu)
+{
+	vcpu->arch.tar = mfspr(SPRN_TAR);
+	vcpu->arch.ebbhr = mfspr(SPRN_EBBHR);
+	vcpu->arch.ebbrr = mfspr(SPRN_EBBRR);
+	vcpu->arch.bescr = mfspr(SPRN_BESCR);
+
+	if (cpu_has_feature(CPU_FTR_P9_TIDR))
+		vcpu->arch.tid = mfspr(SPRN_TIDR);
+	vcpu->arch.iamr = mfspr(SPRN_IAMR);
+	vcpu->arch.amr = mfspr(SPRN_AMR);
+	vcpu->arch.uamor = mfspr(SPRN_UAMOR);
+	vcpu->arch.fscr = mfspr(SPRN_FSCR);
+	vcpu->arch.dscr = mfspr(SPRN_DSCR);
+	vcpu->arch.pspb = mfspr(SPRN_PSPB);
+
+	vcpu->arch.ctrl = mfspr(SPRN_CTRLF);
+}
+
+/* Returns true if current MSR and/or guest MSR may have changed */
+bool load_vcpu_state(struct kvm_vcpu *vcpu,
+		     struct p9_host_os_sprs *host_os_sprs)
+{
+	bool ret = false;
+
+	if (cpu_has_feature(CPU_FTR_TM) ||
+	    cpu_has_feature(CPU_FTR_P9_TM_HV_ASSIST)) {
+		kvmppc_restore_tm_hv(vcpu, vcpu->arch.shregs.msr, true);
+		ret = true;
+	}
+
+	load_spr_state(vcpu, host_os_sprs);
+
+	load_fp_state(&vcpu->arch.fp);
+#ifdef CONFIG_ALTIVEC
+	load_vr_state(&vcpu->arch.vr);
+#endif
+	mtspr(SPRN_VRSAVE, vcpu->arch.vrsave);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(load_vcpu_state);
+
+void store_vcpu_state(struct kvm_vcpu *vcpu)
+{
+	store_spr_state(vcpu);
+
+	store_fp_state(&vcpu->arch.fp);
+#ifdef CONFIG_ALTIVEC
+	store_vr_state(&vcpu->arch.vr);
+#endif
+	vcpu->arch.vrsave = mfspr(SPRN_VRSAVE);
+
+	if (cpu_has_feature(CPU_FTR_TM) ||
+	    cpu_has_feature(CPU_FTR_P9_TM_HV_ASSIST))
+		kvmppc_save_tm_hv(vcpu, vcpu->arch.shregs.msr, true);
+}
+EXPORT_SYMBOL_GPL(store_vcpu_state);
+
+void save_p9_host_os_sprs(struct p9_host_os_sprs *host_os_sprs)
+{
+	if (cpu_has_feature(CPU_FTR_P9_TIDR))
+		host_os_sprs->tidr = mfspr(SPRN_TIDR);
+	host_os_sprs->iamr = mfspr(SPRN_IAMR);
+	host_os_sprs->amr = mfspr(SPRN_AMR);
+	host_os_sprs->fscr = mfspr(SPRN_FSCR);
+	host_os_sprs->dscr = mfspr(SPRN_DSCR);
+}
+EXPORT_SYMBOL_GPL(save_p9_host_os_sprs);
+
+/* vcpu guest regs must already be saved */
+void restore_p9_host_os_sprs(struct kvm_vcpu *vcpu,
+			     struct p9_host_os_sprs *host_os_sprs)
+{
+	mtspr(SPRN_SPRG_VDSO_WRITE, local_paca->sprg_vdso);
+
+	if (cpu_has_feature(CPU_FTR_P9_TIDR))
+		mtspr(SPRN_TIDR, host_os_sprs->tidr);
+	if (host_os_sprs->iamr != vcpu->arch.iamr)
+		mtspr(SPRN_IAMR, host_os_sprs->iamr);
+	if (vcpu->arch.uamor != 0)
+		mtspr(SPRN_UAMOR, 0);
+	if (host_os_sprs->amr != vcpu->arch.amr)
+		mtspr(SPRN_AMR, host_os_sprs->amr);
+	if (host_os_sprs->fscr != vcpu->arch.fscr)
+		mtspr(SPRN_FSCR, host_os_sprs->fscr);
+	if (host_os_sprs->dscr != vcpu->arch.dscr)
+		mtspr(SPRN_DSCR, host_os_sprs->dscr);
+	if (vcpu->arch.pspb != 0)
+		mtspr(SPRN_PSPB, 0);
+
+	/* Save guest CTRL register, set runlatch to 1 */
+	if (!(vcpu->arch.ctrl & 1))
+		mtspr(SPRN_CTRLT, 1);
+}
+EXPORT_SYMBOL_GPL(restore_p9_host_os_sprs);
+
 #ifdef CONFIG_KVM_BOOK3S_HV_EXIT_TIMING
 static void __start_timing(struct kvm_vcpu *vcpu, struct kvmhv_tb_accumulator *next)
 {
-- 
2.23.0

[PATCH v4 30/53] KVM: PPC: Book3S HV P9: Move nested guest entry into its own function

[Nicholas Piggin]

Move the part of the guest entry which is specific to nested HV into its
own function. This is just refactoring.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/kvm/book3s_hv.c | 125 +++++++++++++++++++----------------
 1 file changed, 67 insertions(+), 58 deletions(-)

diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 8a9d2314d67c..69631309b6af 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -3822,6 +3822,72 @@ static void vcpu_vpa_increment_dispatch(struct kvm_vcpu *vcpu)
 	}
 }
 
+/* call our hypervisor to load up HV regs and go */
+static int kvmhv_vcpu_entry_p9_nested(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpcr, u64 *tb)
+{
+	struct kvmppc_vcore *vc = vcpu->arch.vcore;
+	unsigned long host_psscr;
+	struct hv_guest_state hvregs;
+	int trap;
+	s64 dec;
+
+	/*
+	 * We need to save and restore the guest visible part of the
+	 * psscr (i.e. using SPRN_PSSCR_PR) since the hypervisor
+	 * doesn't do this for us. Note only required if pseries since
+	 * this is done in kvmhv_vcpu_entry_p9() below otherwise.
+	 */
+	host_psscr = mfspr(SPRN_PSSCR_PR);
+	mtspr(SPRN_PSSCR_PR, vcpu->arch.psscr);
+	kvmhv_save_hv_regs(vcpu, &hvregs);
+	hvregs.lpcr = lpcr;
+	vcpu->arch.regs.msr = vcpu->arch.shregs.msr;
+	hvregs.version = HV_GUEST_STATE_VERSION;
+	if (vcpu->arch.nested) {
+		hvregs.lpid = vcpu->arch.nested->shadow_lpid;
+		hvregs.vcpu_token = vcpu->arch.nested_vcpu_id;
+	} else {
+		hvregs.lpid = vcpu->kvm->arch.lpid;
+		hvregs.vcpu_token = vcpu->vcpu_id;
+	}
+	hvregs.hdec_expiry = time_limit;
+
+	/*
+	 * When setting DEC, we must always deal with irq_work_raise
+	 * via NMI vs setting DEC. The problem occurs right as we
+	 * switch into guest mode if a NMI hits and sets pending work
+	 * and sets DEC, then that will apply to the guest and not
+	 * bring us back to the host.
+	 *
+	 * irq_work_raise could check a flag (or possibly LPCR[HDICE]
+	 * for example) and set HDEC to 1? That wouldn't solve the
+	 * nested hv case which needs to abort the hcall or zero the
+	 * time limit.
+	 *
+	 * XXX: Another day's problem.
+	 */
+	mtspr(SPRN_DEC, kvmppc_dec_expires_host_tb(vcpu) - *tb);
+
+	mtspr(SPRN_DAR, vcpu->arch.shregs.dar);
+	mtspr(SPRN_DSISR, vcpu->arch.shregs.dsisr);
+	trap = plpar_hcall_norets(H_ENTER_NESTED, __pa(&hvregs),
+				  __pa(&vcpu->arch.regs));
+	kvmhv_restore_hv_return_state(vcpu, &hvregs);
+	vcpu->arch.shregs.msr = vcpu->arch.regs.msr;
+	vcpu->arch.shregs.dar = mfspr(SPRN_DAR);
+	vcpu->arch.shregs.dsisr = mfspr(SPRN_DSISR);
+	vcpu->arch.psscr = mfspr(SPRN_PSSCR_PR);
+	mtspr(SPRN_PSSCR_PR, host_psscr);
+
+	dec = mfspr(SPRN_DEC);
+	if (!(lpcr & LPCR_LD)) /* Sign extend if not using large decrementer */
+		dec = (s32) dec;
+	*tb = mftb();
+	vcpu->arch.dec_expires = dec + (*tb + vc->tb_offset);
+
+	return trap;
+}
+
 /*
  * Guest entry for POWER9 and later CPUs.
  */
@@ -3830,7 +3896,6 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
 {
 	struct kvmppc_vcore *vc = vcpu->arch.vcore;
 	struct p9_host_os_sprs host_os_sprs;
-	s64 dec;
 	u64 next_timer;
 	unsigned long msr;
 	int trap;
@@ -3883,63 +3948,7 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
 	switch_pmu_to_guest(vcpu, &host_os_sprs);
 
 	if (kvmhv_on_pseries()) {
-		/*
-		 * We need to save and restore the guest visible part of the
-		 * psscr (i.e. using SPRN_PSSCR_PR) since the hypervisor
-		 * doesn't do this for us. Note only required if pseries since
-		 * this is done in kvmhv_vcpu_entry_p9() below otherwise.
-		 */
-		unsigned long host_psscr;
-		/* call our hypervisor to load up HV regs and go */
-		struct hv_guest_state hvregs;
-
-		host_psscr = mfspr(SPRN_PSSCR_PR);
-		mtspr(SPRN_PSSCR_PR, vcpu->arch.psscr);
-		kvmhv_save_hv_regs(vcpu, &hvregs);
-		hvregs.lpcr = lpcr;
-		vcpu->arch.regs.msr = vcpu->arch.shregs.msr;
-		hvregs.version = HV_GUEST_STATE_VERSION;
-		if (vcpu->arch.nested) {
-			hvregs.lpid = vcpu->arch.nested->shadow_lpid;
-			hvregs.vcpu_token = vcpu->arch.nested_vcpu_id;
-		} else {
-			hvregs.lpid = vcpu->kvm->arch.lpid;
-			hvregs.vcpu_token = vcpu->vcpu_id;
-		}
-		hvregs.hdec_expiry = time_limit;
-
-		/*
-		 * When setting DEC, we must always deal with irq_work_raise
-		 * via NMI vs setting DEC. The problem occurs right as we
-		 * switch into guest mode if a NMI hits and sets pending work
-		 * and sets DEC, then that will apply to the guest and not
-		 * bring us back to the host.
-		 *
-		 * irq_work_raise could check a flag (or possibly LPCR[HDICE]
-		 * for example) and set HDEC to 1? That wouldn't solve the
-		 * nested hv case which needs to abort the hcall or zero the
-		 * time limit.
-		 *
-		 * XXX: Another day's problem.
-		 */
-		mtspr(SPRN_DEC, kvmppc_dec_expires_host_tb(vcpu) - *tb);
-
-		mtspr(SPRN_DAR, vcpu->arch.shregs.dar);
-		mtspr(SPRN_DSISR, vcpu->arch.shregs.dsisr);
-		trap = plpar_hcall_norets(H_ENTER_NESTED, __pa(&hvregs),
-					  __pa(&vcpu->arch.regs));
-		kvmhv_restore_hv_return_state(vcpu, &hvregs);
-		vcpu->arch.shregs.msr = vcpu->arch.regs.msr;
-		vcpu->arch.shregs.dar = mfspr(SPRN_DAR);
-		vcpu->arch.shregs.dsisr = mfspr(SPRN_DSISR);
-		vcpu->arch.psscr = mfspr(SPRN_PSSCR_PR);
-		mtspr(SPRN_PSSCR_PR, host_psscr);
-
-		dec = mfspr(SPRN_DEC);
-		if (!(lpcr & LPCR_LD)) /* Sign extend if not using large decrementer */
-			dec = (s32) dec;
-		*tb = mftb();
-		vcpu->arch.dec_expires = dec + (*tb + vc->tb_offset);
+		trap = kvmhv_vcpu_entry_p9_nested(vcpu, time_limit, lpcr, tb);
 
 		/* H_CEDE has to be handled now, not later */
 		if (trap == BOOK3S_INTERRUPT_SYSCALL && !vcpu->arch.nested &&
-- 
2.23.0

[PATCH v4 31/53] KVM: PPC: Book3S HV P9: Move remaining SPR and MSR access into low level entry

[Nicholas Piggin]

Move register saving and loading from kvmhv_p9_guest_entry() into the HV
and nested entry handlers.

Accesses are scheduled to reduce mtSPR / mfSPR interleaving which
reduces SPR scoreboard stalls.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/kvm/book3s_hv.c          | 79 ++++++++++------------
 arch/powerpc/kvm/book3s_hv_p9_entry.c | 96 ++++++++++++++++++++-------
 2 files changed, 109 insertions(+), 66 deletions(-)

diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 69631309b6af..40bee0d61482 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -3827,9 +3827,15 @@ static int kvmhv_vcpu_entry_p9_nested(struct kvm_vcpu *vcpu, u64 time_limit, uns
 {
 	struct kvmppc_vcore *vc = vcpu->arch.vcore;
 	unsigned long host_psscr;
+	unsigned long msr;
 	struct hv_guest_state hvregs;
-	int trap;
+	struct p9_host_os_sprs host_os_sprs;
 	s64 dec;
+	int trap;
+
+	switch_pmu_to_guest(vcpu, &host_os_sprs);
+
+	save_p9_host_os_sprs(&host_os_sprs);
 
 	/*
 	 * We need to save and restore the guest visible part of the
@@ -3838,6 +3844,27 @@ static int kvmhv_vcpu_entry_p9_nested(struct kvm_vcpu *vcpu, u64 time_limit, uns
 	 * this is done in kvmhv_vcpu_entry_p9() below otherwise.
 	 */
 	host_psscr = mfspr(SPRN_PSSCR_PR);
+
+	hard_irq_disable();
+	if (lazy_irq_pending())
+		return 0;
+
+	/* MSR bits may have been cleared by context switch */
+	msr = 0;
+	if (IS_ENABLED(CONFIG_PPC_FPU))
+		msr |= MSR_FP;
+	if (cpu_has_feature(CPU_FTR_ALTIVEC))
+		msr |= MSR_VEC;
+	if (cpu_has_feature(CPU_FTR_VSX))
+		msr |= MSR_VSX;
+	if (cpu_has_feature(CPU_FTR_TM) ||
+	    cpu_has_feature(CPU_FTR_P9_TM_HV_ASSIST))
+		msr |= MSR_TM;
+	msr = msr_check_and_set(msr);
+
+	if (unlikely(load_vcpu_state(vcpu, &host_os_sprs)))
+		msr = mfmsr(); /* TM restore can update msr */
+
 	mtspr(SPRN_PSSCR_PR, vcpu->arch.psscr);
 	kvmhv_save_hv_regs(vcpu, &hvregs);
 	hvregs.lpcr = lpcr;
@@ -3879,12 +3906,20 @@ static int kvmhv_vcpu_entry_p9_nested(struct kvm_vcpu *vcpu, u64 time_limit, uns
 	vcpu->arch.psscr = mfspr(SPRN_PSSCR_PR);
 	mtspr(SPRN_PSSCR_PR, host_psscr);
 
+	store_vcpu_state(vcpu);
+
 	dec = mfspr(SPRN_DEC);
 	if (!(lpcr & LPCR_LD)) /* Sign extend if not using large decrementer */
 		dec = (s32) dec;
 	*tb = mftb();
 	vcpu->arch.dec_expires = dec + (*tb + vc->tb_offset);
 
+	timer_rearm_host_dec(*tb);
+
+	restore_p9_host_os_sprs(vcpu, &host_os_sprs);
+
+	switch_pmu_to_host(vcpu, &host_os_sprs);
+
 	return trap;
 }
 
@@ -3895,9 +3930,7 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
 			 unsigned long lpcr, u64 *tb)
 {
 	struct kvmppc_vcore *vc = vcpu->arch.vcore;
-	struct p9_host_os_sprs host_os_sprs;
 	u64 next_timer;
-	unsigned long msr;
 	int trap;
 
 	next_timer = timer_get_next_tb();
@@ -3908,33 +3941,6 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
 
 	vcpu->arch.ceded = 0;
 
-	save_p9_host_os_sprs(&host_os_sprs);
-
-	/*
-	 * This could be combined with MSR[RI] clearing, but that expands
-	 * the unrecoverable window. It would be better to cover unrecoverable
-	 * with KVM bad interrupt handling rather than use MSR[RI] at all.
-	 *
-	 * Much more difficult and less worthwhile to combine with IR/DR
-	 * disable.
-	 */
-	hard_irq_disable();
-	if (lazy_irq_pending())
-		return 0;
-
-	/* MSR bits may have been cleared by context switch */
-	msr = 0;
-	if (IS_ENABLED(CONFIG_PPC_FPU))
-		msr |= MSR_FP;
-	if (cpu_has_feature(CPU_FTR_ALTIVEC))
-		msr |= MSR_VEC;
-	if (cpu_has_feature(CPU_FTR_VSX))
-		msr |= MSR_VSX;
-	if (cpu_has_feature(CPU_FTR_TM) ||
-	    cpu_has_feature(CPU_FTR_P9_TM_HV_ASSIST))
-		msr |= MSR_TM;
-	msr = msr_check_and_set(msr);
-
 	kvmppc_subcore_enter_guest();
 
 	vc->entry_exit_map = 1;
@@ -3942,11 +3948,6 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
 
 	vcpu_vpa_increment_dispatch(vcpu);
 
-	if (unlikely(load_vcpu_state(vcpu, &host_os_sprs)))
-		msr = mfmsr(); /* MSR may have been updated */
-
-	switch_pmu_to_guest(vcpu, &host_os_sprs);
-
 	if (kvmhv_on_pseries()) {
 		trap = kvmhv_vcpu_entry_p9_nested(vcpu, time_limit, lpcr, tb);
 
@@ -3989,16 +3990,8 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
 			vcpu->arch.slb_max = 0;
 	}
 
-	switch_pmu_to_host(vcpu, &host_os_sprs);
-
-	store_vcpu_state(vcpu);
-
 	vcpu_vpa_increment_dispatch(vcpu);
 
-	timer_rearm_host_dec(*tb);
-
-	restore_p9_host_os_sprs(vcpu, &host_os_sprs);
-
 	vc->entry_exit_map = 0x101;
 	vc->in_guest = 0;
 
diff --git a/arch/powerpc/kvm/book3s_hv_p9_entry.c b/arch/powerpc/kvm/book3s_hv_p9_entry.c
index 784ff5429ebc..fa080533bd8d 100644
--- a/arch/powerpc/kvm/book3s_hv_p9_entry.c
+++ b/arch/powerpc/kvm/book3s_hv_p9_entry.c
@@ -538,6 +538,7 @@ static void save_clear_guest_mmu(struct kvm *kvm, struct kvm_vcpu *vcpu)
 
 int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpcr, u64 *tb)
 {
+	struct p9_host_os_sprs host_os_sprs;
 	struct kvm *kvm = vcpu->kvm;
 	struct kvm_nested_guest *nested = vcpu->arch.nested;
 	struct kvmppc_vcore *vc = vcpu->arch.vcore;
@@ -567,9 +568,6 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
 
 	vcpu->arch.ceded = 0;
 
-	/* Could avoid mfmsr by passing around, but probably no big deal */
-	msr = mfmsr();
-
 	host_hfscr = mfspr(SPRN_HFSCR);
 	host_ciabr = mfspr(SPRN_CIABR);
 	host_dawr0 = mfspr(SPRN_DAWR0);
@@ -584,6 +582,41 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
 	local_paca->kvm_hstate.host_purr = mfspr(SPRN_PURR);
 	local_paca->kvm_hstate.host_spurr = mfspr(SPRN_SPURR);
 
+	switch_pmu_to_guest(vcpu, &host_os_sprs);
+
+	save_p9_host_os_sprs(&host_os_sprs);
+
+	/*
+	 * This could be combined with MSR[RI] clearing, but that expands
+	 * the unrecoverable window. It would be better to cover unrecoverable
+	 * with KVM bad interrupt handling rather than use MSR[RI] at all.
+	 *
+	 * Much more difficult and less worthwhile to combine with IR/DR
+	 * disable.
+	 */
+	hard_irq_disable();
+	if (lazy_irq_pending()) {
+		trap = 0;
+		goto out;
+	}
+
+	/* MSR bits may have been cleared by context switch */
+	msr = 0;
+	if (IS_ENABLED(CONFIG_PPC_FPU))
+		msr |= MSR_FP;
+	if (cpu_has_feature(CPU_FTR_ALTIVEC))
+		msr |= MSR_VEC;
+	if (cpu_has_feature(CPU_FTR_VSX))
+		msr |= MSR_VSX;
+	if (cpu_has_feature(CPU_FTR_TM) ||
+	    cpu_has_feature(CPU_FTR_P9_TM_HV_ASSIST))
+		msr |= MSR_TM;
+	msr = msr_check_and_set(msr);
+	/* Save MSR for restore. This is after hard disable, so EE is clear. */
+
+	if (unlikely(load_vcpu_state(vcpu, &host_os_sprs)))
+		msr = mfmsr(); /* MSR may have been updated */
+
 	if (vc->tb_offset) {
 		u64 new_tb = *tb + vc->tb_offset;
 		mtspr(SPRN_TBU40, new_tb);
@@ -642,6 +675,14 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
 	mtspr(SPRN_SPRG2, vcpu->arch.shregs.sprg2);
 	mtspr(SPRN_SPRG3, vcpu->arch.shregs.sprg3);
 
+	/*
+	 * It might be preferable to load_vcpu_state here, in order to get the
+	 * GPR/FP register loads executing in parallel with the previous mtSPR
+	 * instructions, but for now that can't be done because the TM handling
+	 * in load_vcpu_state can change some SPRs and vcpu state (nip, msr).
+	 * But TM could be split out if this would be a significant benefit.
+	 */
+
 	local_paca->kvm_hstate.in_guest = KVM_GUEST_MODE_HV_P9;
 
 	/*
@@ -819,6 +860,20 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
 	vc->dpdes = mfspr(SPRN_DPDES);
 	vc->vtb = mfspr(SPRN_VTB);
 
+	save_clear_guest_mmu(kvm, vcpu);
+	switch_mmu_to_host(kvm, host_pidr);
+
+	/*
+	 * If we are in real mode, only switch MMU on after the MMU is
+	 * switched to host, to avoid the P9_RADIX_PREFETCH_BUG.
+	 */
+	if (IS_ENABLED(CONFIG_PPC_TRANSACTIONAL_MEM) &&
+			vcpu->arch.shregs.msr & MSR_TS_MASK)
+		msr |= MSR_TS_S;
+	__mtmsrd(msr, 0);
+
+	store_vcpu_state(vcpu);
+
 	dec = mfspr(SPRN_DEC);
 	if (!(lpcr & LPCR_LD)) /* Sign extend if not using large decrementer */
 		dec = (s32) dec;
@@ -851,6 +906,19 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
 		mtspr(SPRN_DAWRX1, host_dawrx1);
 	}
 
+	mtspr(SPRN_DPDES, 0);
+	if (vc->pcr)
+		mtspr(SPRN_PCR, PCR_MASK);
+
+	/* HDEC must be at least as large as DEC, so decrementer_max fits */
+	mtspr(SPRN_HDEC, decrementer_max);
+
+	timer_rearm_host_dec(*tb);
+
+	restore_p9_host_os_sprs(vcpu, &host_os_sprs);
+
+	local_paca->kvm_hstate.in_guest = KVM_GUEST_MODE_NONE;
+
 	if (kvm_is_radix(kvm)) {
 		/*
 		 * Since this is radix, do a eieio; tlbsync; ptesync sequence
@@ -867,26 +935,8 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
 	if (cpu_has_feature(CPU_FTR_ARCH_31))
 		asm volatile(PPC_CP_ABORT);
 
-	mtspr(SPRN_DPDES, 0);
-	if (vc->pcr)
-		mtspr(SPRN_PCR, PCR_MASK);
-
-	/* HDEC must be at least as large as DEC, so decrementer_max fits */
-	mtspr(SPRN_HDEC, decrementer_max);
-
-	save_clear_guest_mmu(kvm, vcpu);
-	switch_mmu_to_host(kvm, host_pidr);
-	local_paca->kvm_hstate.in_guest = KVM_GUEST_MODE_NONE;
-
-	/*
-	 * If we are in real mode, only switch MMU on after the MMU is
-	 * switched to host, to avoid the P9_RADIX_PREFETCH_BUG.
-	 */
-	if (IS_ENABLED(CONFIG_PPC_TRANSACTIONAL_MEM) &&
-	    vcpu->arch.shregs.msr & MSR_TS_MASK)
-		msr |= MSR_TS_S;
-
-	__mtmsrd(msr, 0);
+out:
+	switch_pmu_to_host(vcpu, &host_os_sprs);
 
 	end_timing(vcpu);
 
-- 
2.23.0

[PATCH v4 32/53] KVM: PPC: Book3S HV P9: Implement TM fastpath for guest entry/exit

[Nicholas Piggin]

If TM is not active, only TM register state needs to be saved and
restored, avoiding several mfmsr/mtmsrd instructions and improving
performance.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/kvm/book3s_hv_p9_entry.c | 27 +++++++++++++++++++++++----
 1 file changed, 23 insertions(+), 4 deletions(-)

diff --git a/arch/powerpc/kvm/book3s_hv_p9_entry.c b/arch/powerpc/kvm/book3s_hv_p9_entry.c
index fa080533bd8d..6bef509bccb8 100644
--- a/arch/powerpc/kvm/book3s_hv_p9_entry.c
+++ b/arch/powerpc/kvm/book3s_hv_p9_entry.c
@@ -287,11 +287,20 @@ bool load_vcpu_state(struct kvm_vcpu *vcpu,
 {
 	bool ret = false;
 
+#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
 	if (cpu_has_feature(CPU_FTR_TM) ||
 	    cpu_has_feature(CPU_FTR_P9_TM_HV_ASSIST)) {
-		kvmppc_restore_tm_hv(vcpu, vcpu->arch.shregs.msr, true);
-		ret = true;
+		unsigned long guest_msr = vcpu->arch.shregs.msr;
+		if (MSR_TM_ACTIVE(guest_msr)) {
+			kvmppc_restore_tm_hv(vcpu, guest_msr, true);
+			ret = true;
+		} else {
+			mtspr(SPRN_TEXASR, vcpu->arch.texasr);
+			mtspr(SPRN_TFHAR, vcpu->arch.tfhar);
+			mtspr(SPRN_TFIAR, vcpu->arch.tfiar);
+		}
 	}
+#endif
 
 	load_spr_state(vcpu, host_os_sprs);
 
@@ -315,9 +324,19 @@ void store_vcpu_state(struct kvm_vcpu *vcpu)
 #endif
 	vcpu->arch.vrsave = mfspr(SPRN_VRSAVE);
 
+#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
 	if (cpu_has_feature(CPU_FTR_TM) ||
-	    cpu_has_feature(CPU_FTR_P9_TM_HV_ASSIST))
-		kvmppc_save_tm_hv(vcpu, vcpu->arch.shregs.msr, true);
+	    cpu_has_feature(CPU_FTR_P9_TM_HV_ASSIST)) {
+		unsigned long guest_msr = vcpu->arch.shregs.msr;
+		if (MSR_TM_ACTIVE(guest_msr)) {
+			kvmppc_save_tm_hv(vcpu, guest_msr, true);
+		} else {
+			vcpu->arch.texasr = mfspr(SPRN_TEXASR);
+			vcpu->arch.tfhar = mfspr(SPRN_TFHAR);
+			vcpu->arch.tfiar = mfspr(SPRN_TFIAR);
+		}
+	}
+#endif
 }
 EXPORT_SYMBOL_GPL(store_vcpu_state);
 
-- 
2.23.0

[PATCH v4 33/53] KVM: PPC: Book3S HV P9: Switch PMU to guest as late as possible

[Nicholas Piggin]

This moves PMU switch to guest as late as possible in entry, and switch
back to host as early as possible at exit. This helps the host get the
most perf coverage of KVM entry/exit code as possible.

This is slightly suboptimal for SPR scheduling point of view when the
PMU is enabled, but when perf is disabled there is no real difference.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/kvm/book3s_hv.c          | 6 ++----
 arch/powerpc/kvm/book3s_hv_p9_entry.c | 6 ++----
 2 files changed, 4 insertions(+), 8 deletions(-)

diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 40bee0d61482..c14467cf23d3 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -3833,8 +3833,6 @@ static int kvmhv_vcpu_entry_p9_nested(struct kvm_vcpu *vcpu, u64 time_limit, uns
 	s64 dec;
 	int trap;
 
-	switch_pmu_to_guest(vcpu, &host_os_sprs);
-
 	save_p9_host_os_sprs(&host_os_sprs);
 
 	/*
@@ -3897,9 +3895,11 @@ static int kvmhv_vcpu_entry_p9_nested(struct kvm_vcpu *vcpu, u64 time_limit, uns
 
 	mtspr(SPRN_DAR, vcpu->arch.shregs.dar);
 	mtspr(SPRN_DSISR, vcpu->arch.shregs.dsisr);
+	switch_pmu_to_guest(vcpu, &host_os_sprs);
 	trap = plpar_hcall_norets(H_ENTER_NESTED, __pa(&hvregs),
 				  __pa(&vcpu->arch.regs));
 	kvmhv_restore_hv_return_state(vcpu, &hvregs);
+	switch_pmu_to_host(vcpu, &host_os_sprs);
 	vcpu->arch.shregs.msr = vcpu->arch.regs.msr;
 	vcpu->arch.shregs.dar = mfspr(SPRN_DAR);
 	vcpu->arch.shregs.dsisr = mfspr(SPRN_DSISR);
@@ -3918,8 +3918,6 @@ static int kvmhv_vcpu_entry_p9_nested(struct kvm_vcpu *vcpu, u64 time_limit, uns
 
 	restore_p9_host_os_sprs(vcpu, &host_os_sprs);
 
-	switch_pmu_to_host(vcpu, &host_os_sprs);
-
 	return trap;
 }
 
diff --git a/arch/powerpc/kvm/book3s_hv_p9_entry.c b/arch/powerpc/kvm/book3s_hv_p9_entry.c
index 6bef509bccb8..619bbcd47b92 100644
--- a/arch/powerpc/kvm/book3s_hv_p9_entry.c
+++ b/arch/powerpc/kvm/book3s_hv_p9_entry.c
@@ -601,8 +601,6 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
 	local_paca->kvm_hstate.host_purr = mfspr(SPRN_PURR);
 	local_paca->kvm_hstate.host_spurr = mfspr(SPRN_SPURR);
 
-	switch_pmu_to_guest(vcpu, &host_os_sprs);
-
 	save_p9_host_os_sprs(&host_os_sprs);
 
 	/*
@@ -744,7 +742,9 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
 
 	accumulate_time(vcpu, &vcpu->arch.guest_time);
 
+	switch_pmu_to_guest(vcpu, &host_os_sprs);
 	kvmppc_p9_enter_guest(vcpu);
+	switch_pmu_to_host(vcpu, &host_os_sprs);
 
 	accumulate_time(vcpu, &vcpu->arch.rm_intr);
 
@@ -955,8 +955,6 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
 		asm volatile(PPC_CP_ABORT);
 
 out:
-	switch_pmu_to_host(vcpu, &host_os_sprs);
-
 	end_timing(vcpu);
 
 	return trap;
-- 
2.23.0

[PATCH v4 34/53] KVM: PPC: Book3S HV P9: Restrict DSISR canary workaround to processors that require it

[Nicholas Piggin]

Use CPU_FTR_P9_RADIX_PREFETCH_BUG to apply the workaround, to test for
DD2.1 and below processors. This saves a mtSPR in guest entry.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/kvm/book3s_hv.c          | 3 ++-
 arch/powerpc/kvm/book3s_hv_p9_entry.c | 6 ++++--
 2 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index c14467cf23d3..3795080d5403 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -1590,7 +1590,8 @@ static int kvmppc_handle_exit_hv(struct kvm_vcpu *vcpu,
 		unsigned long vsid;
 		long err;
 
-		if (vcpu->arch.fault_dsisr == HDSISR_CANARY) {
+		if (cpu_has_feature(CPU_FTR_P9_RADIX_PREFETCH_BUG) &&
+		    unlikely(vcpu->arch.fault_dsisr == HDSISR_CANARY)) {
 			r = RESUME_GUEST; /* Just retry if it's the canary */
 			break;
 		}
diff --git a/arch/powerpc/kvm/book3s_hv_p9_entry.c b/arch/powerpc/kvm/book3s_hv_p9_entry.c
index 619bbcd47b92..67f57b03a896 100644
--- a/arch/powerpc/kvm/book3s_hv_p9_entry.c
+++ b/arch/powerpc/kvm/book3s_hv_p9_entry.c
@@ -683,9 +683,11 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
 	 * HDSI which should correctly update the HDSISR the second time HDSI
 	 * entry.
 	 *
-	 * Just do this on all p9 processors for now.
+	 * The "radix prefetch bug" test can be used to test for this bug, as
+	 * it also exists fo DD2.1 and below.
 	 */
-	mtspr(SPRN_HDSISR, HDSISR_CANARY);
+	if (cpu_has_feature(CPU_FTR_P9_RADIX_PREFETCH_BUG))
+		mtspr(SPRN_HDSISR, HDSISR_CANARY);
 
 	mtspr(SPRN_SPRG0, vcpu->arch.shregs.sprg0);
 	mtspr(SPRN_SPRG1, vcpu->arch.shregs.sprg1);
-- 
2.23.0

[PATCH v4 35/53] KVM: PPC: Book3S HV P9: More SPR speed improvements

[Nicholas Piggin]

This avoids more scoreboard stalls and reduces mtSPRs.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/kvm/book3s_hv_p9_entry.c | 73 ++++++++++++++++-----------
 1 file changed, 43 insertions(+), 30 deletions(-)

diff --git a/arch/powerpc/kvm/book3s_hv_p9_entry.c b/arch/powerpc/kvm/book3s_hv_p9_entry.c
index 67f57b03a896..a23f09fa7d2d 100644
--- a/arch/powerpc/kvm/book3s_hv_p9_entry.c
+++ b/arch/powerpc/kvm/book3s_hv_p9_entry.c
@@ -645,24 +645,29 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
 		vc->tb_offset_applied = vc->tb_offset;
 	}
 
-	if (vc->pcr)
-		mtspr(SPRN_PCR, vc->pcr | PCR_MASK);
-	mtspr(SPRN_DPDES, vc->dpdes);
 	mtspr(SPRN_VTB, vc->vtb);
-
 	mtspr(SPRN_PURR, vcpu->arch.purr);
 	mtspr(SPRN_SPURR, vcpu->arch.spurr);
 
+	if (vc->pcr)
+		mtspr(SPRN_PCR, vc->pcr | PCR_MASK);
+	if (vc->dpdes)
+		mtspr(SPRN_DPDES, vc->dpdes);
+
 	if (dawr_enabled()) {
-		mtspr(SPRN_DAWR0, vcpu->arch.dawr0);
-		mtspr(SPRN_DAWRX0, vcpu->arch.dawrx0);
+		if (vcpu->arch.dawr0 != host_dawr0)
+			mtspr(SPRN_DAWR0, vcpu->arch.dawr0);
+		if (vcpu->arch.dawrx0 != host_dawrx0)
+			mtspr(SPRN_DAWRX0, vcpu->arch.dawrx0);
 		if (cpu_has_feature(CPU_FTR_DAWR1)) {
-			mtspr(SPRN_DAWR1, vcpu->arch.dawr1);
-			mtspr(SPRN_DAWRX1, vcpu->arch.dawrx1);
+			if (vcpu->arch.dawr1 != host_dawr1)
+				mtspr(SPRN_DAWR1, vcpu->arch.dawr1);
+			if (vcpu->arch.dawrx1 != host_dawrx1)
+				mtspr(SPRN_DAWRX1, vcpu->arch.dawrx1);
 		}
 	}
-	mtspr(SPRN_CIABR, vcpu->arch.ciabr);
-	mtspr(SPRN_IC, vcpu->arch.ic);
+	if (vcpu->arch.ciabr != host_ciabr)
+		mtspr(SPRN_CIABR, vcpu->arch.ciabr);
 
 	mtspr(SPRN_PSSCR, vcpu->arch.psscr | PSSCR_EC |
 	      (local_paca->kvm_hstate.fake_suspend << PSSCR_FAKE_SUSPEND_LG));
@@ -881,20 +886,6 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
 	vc->dpdes = mfspr(SPRN_DPDES);
 	vc->vtb = mfspr(SPRN_VTB);
 
-	save_clear_guest_mmu(kvm, vcpu);
-	switch_mmu_to_host(kvm, host_pidr);
-
-	/*
-	 * If we are in real mode, only switch MMU on after the MMU is
-	 * switched to host, to avoid the P9_RADIX_PREFETCH_BUG.
-	 */
-	if (IS_ENABLED(CONFIG_PPC_TRANSACTIONAL_MEM) &&
-			vcpu->arch.shregs.msr & MSR_TS_MASK)
-		msr |= MSR_TS_S;
-	__mtmsrd(msr, 0);
-
-	store_vcpu_state(vcpu);
-
 	dec = mfspr(SPRN_DEC);
 	if (!(lpcr & LPCR_LD)) /* Sign extend if not using large decrementer */
 		dec = (s32) dec;
@@ -912,6 +903,22 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
 		vc->tb_offset_applied = 0;
 	}
 
+	save_clear_guest_mmu(kvm, vcpu);
+	switch_mmu_to_host(kvm, host_pidr);
+
+	/*
+	 * Enable MSR here in order to have facilities enabled to save
+	 * guest registers. This enables MMU (if we were in realmode), so
+	 * only switch MMU on after the MMU is switched to host, to avoid
+	 * the P9_RADIX_PREFETCH_BUG or hash guest context.
+	 */
+	if (IS_ENABLED(CONFIG_PPC_TRANSACTIONAL_MEM) &&
+			vcpu->arch.shregs.msr & MSR_TS_MASK)
+		msr |= MSR_TS_S;
+	__mtmsrd(msr, 0);
+
+	store_vcpu_state(vcpu);
+
 	mtspr(SPRN_PURR, local_paca->kvm_hstate.host_purr);
 	mtspr(SPRN_SPURR, local_paca->kvm_hstate.host_spurr);
 
@@ -919,15 +926,21 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
 	mtspr(SPRN_PSSCR, host_psscr |
 	      (local_paca->kvm_hstate.fake_suspend << PSSCR_FAKE_SUSPEND_LG));
 	mtspr(SPRN_HFSCR, host_hfscr);
-	mtspr(SPRN_CIABR, host_ciabr);
-	mtspr(SPRN_DAWR0, host_dawr0);
-	mtspr(SPRN_DAWRX0, host_dawrx0);
+	if (vcpu->arch.ciabr != host_ciabr)
+		mtspr(SPRN_CIABR, host_ciabr);
+	if (vcpu->arch.dawr0 != host_dawr0)
+		mtspr(SPRN_DAWR0, host_dawr0);
+	if (vcpu->arch.dawrx0 != host_dawrx0)
+		mtspr(SPRN_DAWRX0, host_dawrx0);
 	if (cpu_has_feature(CPU_FTR_DAWR1)) {
-		mtspr(SPRN_DAWR1, host_dawr1);
-		mtspr(SPRN_DAWRX1, host_dawrx1);
+		if (vcpu->arch.dawr1 != host_dawr1)
+			mtspr(SPRN_DAWR1, host_dawr1);
+		if (vcpu->arch.dawrx1 != host_dawrx1)
+			mtspr(SPRN_DAWRX1, host_dawrx1);
 	}
 
-	mtspr(SPRN_DPDES, 0);
+	if (vc->dpdes)
+		mtspr(SPRN_DPDES, 0);
 	if (vc->pcr)
 		mtspr(SPRN_PCR, PCR_MASK);
 
-- 
2.23.0

[PATCH v4 36/53] KVM: PPC: Book3S HV P9: Demand fault EBB facility registers

[Nicholas Piggin]

Use HFSCR facility disabling to implement demand faulting for EBB, with
a hysteresis counter similar to the load_fp etc counters in context
switching that implement the equivalent demand faulting for userspace
facilities.

This speeds up guest entry/exit by avoiding the register save/restore
when a guest is not frequently using them. When a guest does use them
often, there will be some additional demand fault overhead, but these
are not commonly used facilities.

Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/include/asm/kvm_host.h   |  1 +
 arch/powerpc/kvm/book3s_hv.c          | 16 +++++++++++++--
 arch/powerpc/kvm/book3s_hv_p9_entry.c | 28 +++++++++++++++++++++------
 3 files changed, 37 insertions(+), 8 deletions(-)

diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h
index 21ca15c3bc0b..7a55b19eb6c0 100644
--- a/arch/powerpc/include/asm/kvm_host.h
+++ b/arch/powerpc/include/asm/kvm_host.h
@@ -579,6 +579,7 @@ struct kvm_vcpu_arch {
 	ulong cfar;
 	ulong ppr;
 	u32 pspb;
+	u8 load_ebb;
 	ulong fscr;
 	ulong shadow_fscr;
 	ulong ebbhr;
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 3795080d5403..da29cf9236c8 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -1436,6 +1436,16 @@ static int kvmppc_pmu_unavailable(struct kvm_vcpu *vcpu)
 	return RESUME_GUEST;
 }
 
+static int kvmppc_ebb_unavailable(struct kvm_vcpu *vcpu)
+{
+	if (!(vcpu->arch.hfscr_permitted & HFSCR_EBB))
+		return EMULATE_FAIL;
+
+	vcpu->arch.hfscr |= HFSCR_EBB;
+
+	return RESUME_GUEST;
+}
+
 static int kvmppc_handle_exit_hv(struct kvm_vcpu *vcpu,
 				 struct task_struct *tsk)
 {
@@ -1727,6 +1737,8 @@ static int kvmppc_handle_exit_hv(struct kvm_vcpu *vcpu,
 				r = kvmppc_emulate_doorbell_instr(vcpu);
 			if (cause == FSCR_PM_LG)
 				r = kvmppc_pmu_unavailable(vcpu);
+			if (cause == FSCR_EBB_LG)
+				r = kvmppc_ebb_unavailable(vcpu);
 		}
 		if (r == EMULATE_FAIL) {
 			kvmppc_core_queue_program(vcpu, SRR1_PROGILL);
@@ -2771,9 +2783,9 @@ static int kvmppc_core_vcpu_create_hv(struct kvm_vcpu *vcpu)
 	vcpu->arch.hfscr_permitted = vcpu->arch.hfscr;
 
 	/*
-	 * PM is demand-faulted so start with it clear.
+	 * PM, EBB is demand-faulted so start with it clear.
 	 */
-	vcpu->arch.hfscr &= ~HFSCR_PM;
+	vcpu->arch.hfscr &= ~(HFSCR_PM | HFSCR_EBB);
 
 	kvmppc_mmu_book3s_hv_init(vcpu);
 
diff --git a/arch/powerpc/kvm/book3s_hv_p9_entry.c b/arch/powerpc/kvm/book3s_hv_p9_entry.c
index a23f09fa7d2d..929a7c336b09 100644
--- a/arch/powerpc/kvm/book3s_hv_p9_entry.c
+++ b/arch/powerpc/kvm/book3s_hv_p9_entry.c
@@ -232,9 +232,12 @@ static void load_spr_state(struct kvm_vcpu *vcpu,
 				struct p9_host_os_sprs *host_os_sprs)
 {
 	mtspr(SPRN_TAR, vcpu->arch.tar);
-	mtspr(SPRN_EBBHR, vcpu->arch.ebbhr);
-	mtspr(SPRN_EBBRR, vcpu->arch.ebbrr);
-	mtspr(SPRN_BESCR, vcpu->arch.bescr);
+
+	if (vcpu->arch.hfscr & HFSCR_EBB) {
+		mtspr(SPRN_EBBHR, vcpu->arch.ebbhr);
+		mtspr(SPRN_EBBRR, vcpu->arch.ebbrr);
+		mtspr(SPRN_BESCR, vcpu->arch.bescr);
+	}
 
 	if (cpu_has_feature(CPU_FTR_P9_TIDR))
 		mtspr(SPRN_TIDR, vcpu->arch.tid);
@@ -265,9 +268,22 @@ static void load_spr_state(struct kvm_vcpu *vcpu,
 static void store_spr_state(struct kvm_vcpu *vcpu)
 {
 	vcpu->arch.tar = mfspr(SPRN_TAR);
-	vcpu->arch.ebbhr = mfspr(SPRN_EBBHR);
-	vcpu->arch.ebbrr = mfspr(SPRN_EBBRR);
-	vcpu->arch.bescr = mfspr(SPRN_BESCR);
+
+	if (vcpu->arch.hfscr & HFSCR_EBB) {
+		vcpu->arch.ebbhr = mfspr(SPRN_EBBHR);
+		vcpu->arch.ebbrr = mfspr(SPRN_EBBRR);
+		vcpu->arch.bescr = mfspr(SPRN_BESCR);
+		/*
+		 * This is like load_fp in context switching, turn off the
+		 * facility after it wraps the u8 to try avoiding saving
+		 * and restoring the registers each partition switch.
+		 */
+		if (!vcpu->arch.nested) {
+			vcpu->arch.load_ebb++;
+			if (!vcpu->arch.load_ebb)
+				vcpu->arch.hfscr &= ~HFSCR_EBB;
+		}
+	}
 
 	if (cpu_has_feature(CPU_FTR_P9_TIDR))
 		vcpu->arch.tid = mfspr(SPRN_TIDR);
-- 
2.23.0

[PATCH v4 37/53] KVM: PPC: Book3S HV P9: Demand fault TM facility registers

[Nicholas Piggin]

Use HFSCR facility disabling to implement demand faulting for TM, with
a hysteresis counter similar to the load_fp etc counters in context
switching that implement the equivalent demand faulting for userspace
facilities.

This speeds up guest entry/exit by avoiding the register save/restore
when a guest is not frequently using them. When a guest does use them
often, there will be some additional demand fault overhead, but these
are not commonly used facilities.

Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/include/asm/kvm_host.h   |  3 +++
 arch/powerpc/kvm/book3s_hv.c          | 26 ++++++++++++++++++++------
 arch/powerpc/kvm/book3s_hv_p9_entry.c | 15 +++++++++++----
 3 files changed, 34 insertions(+), 10 deletions(-)

diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h
index 7a55b19eb6c0..d7004412b859 100644
--- a/arch/powerpc/include/asm/kvm_host.h
+++ b/arch/powerpc/include/asm/kvm_host.h
@@ -580,6 +580,9 @@ struct kvm_vcpu_arch {
 	ulong ppr;
 	u32 pspb;
 	u8 load_ebb;
+#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
+	u8 load_tm;
+#endif
 	ulong fscr;
 	ulong shadow_fscr;
 	ulong ebbhr;
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index da29cf9236c8..198f6d997330 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -1446,6 +1446,16 @@ static int kvmppc_ebb_unavailable(struct kvm_vcpu *vcpu)
 	return RESUME_GUEST;
 }
 
+static int kvmppc_tm_unavailable(struct kvm_vcpu *vcpu)
+{
+	if (!(vcpu->arch.hfscr_permitted & HFSCR_TM))
+		return EMULATE_FAIL;
+
+	vcpu->arch.hfscr |= HFSCR_TM;
+
+	return RESUME_GUEST;
+}
+
 static int kvmppc_handle_exit_hv(struct kvm_vcpu *vcpu,
 				 struct task_struct *tsk)
 {
@@ -1739,6 +1749,8 @@ static int kvmppc_handle_exit_hv(struct kvm_vcpu *vcpu,
 				r = kvmppc_pmu_unavailable(vcpu);
 			if (cause == FSCR_EBB_LG)
 				r = kvmppc_ebb_unavailable(vcpu);
+			if (cause == FSCR_TM_LG)
+				r = kvmppc_tm_unavailable(vcpu);
 		}
 		if (r == EMULATE_FAIL) {
 			kvmppc_core_queue_program(vcpu, SRR1_PROGILL);
@@ -2783,9 +2795,9 @@ static int kvmppc_core_vcpu_create_hv(struct kvm_vcpu *vcpu)
 	vcpu->arch.hfscr_permitted = vcpu->arch.hfscr;
 
 	/*
-	 * PM, EBB is demand-faulted so start with it clear.
+	 * PM, EBB, TM are demand-faulted so start with it clear.
 	 */
-	vcpu->arch.hfscr &= ~(HFSCR_PM | HFSCR_EBB);
+	vcpu->arch.hfscr &= ~(HFSCR_PM | HFSCR_EBB | HFSCR_TM);
 
 	kvmppc_mmu_book3s_hv_init(vcpu);
 
@@ -3868,8 +3880,9 @@ static int kvmhv_vcpu_entry_p9_nested(struct kvm_vcpu *vcpu, u64 time_limit, uns
 		msr |= MSR_VEC;
 	if (cpu_has_feature(CPU_FTR_VSX))
 		msr |= MSR_VSX;
-	if (cpu_has_feature(CPU_FTR_TM) ||
-	    cpu_has_feature(CPU_FTR_P9_TM_HV_ASSIST))
+	if ((cpu_has_feature(CPU_FTR_TM) ||
+	    cpu_has_feature(CPU_FTR_P9_TM_HV_ASSIST)) &&
+			(vcpu->arch.hfscr & HFSCR_TM))
 		msr |= MSR_TM;
 	msr = msr_check_and_set(msr);
 
@@ -4608,8 +4621,9 @@ static int kvmppc_vcpu_run_hv(struct kvm_vcpu *vcpu)
 		msr |= MSR_VEC;
 	if (cpu_has_feature(CPU_FTR_VSX))
 		msr |= MSR_VSX;
-	if (cpu_has_feature(CPU_FTR_TM) ||
-	    cpu_has_feature(CPU_FTR_P9_TM_HV_ASSIST))
+	if ((cpu_has_feature(CPU_FTR_TM) ||
+	    cpu_has_feature(CPU_FTR_P9_TM_HV_ASSIST)) &&
+			(vcpu->arch.hfscr & HFSCR_TM))
 		msr |= MSR_TM;
 	msr = msr_check_and_set(msr);
 
diff --git a/arch/powerpc/kvm/book3s_hv_p9_entry.c b/arch/powerpc/kvm/book3s_hv_p9_entry.c
index 929a7c336b09..8499e8a9ca8f 100644
--- a/arch/powerpc/kvm/book3s_hv_p9_entry.c
+++ b/arch/powerpc/kvm/book3s_hv_p9_entry.c
@@ -310,7 +310,7 @@ bool load_vcpu_state(struct kvm_vcpu *vcpu,
 		if (MSR_TM_ACTIVE(guest_msr)) {
 			kvmppc_restore_tm_hv(vcpu, guest_msr, true);
 			ret = true;
-		} else {
+		} else if (vcpu->arch.hfscr & HFSCR_TM) {
 			mtspr(SPRN_TEXASR, vcpu->arch.texasr);
 			mtspr(SPRN_TFHAR, vcpu->arch.tfhar);
 			mtspr(SPRN_TFIAR, vcpu->arch.tfiar);
@@ -346,10 +346,16 @@ void store_vcpu_state(struct kvm_vcpu *vcpu)
 		unsigned long guest_msr = vcpu->arch.shregs.msr;
 		if (MSR_TM_ACTIVE(guest_msr)) {
 			kvmppc_save_tm_hv(vcpu, guest_msr, true);
-		} else {
+		} else if (vcpu->arch.hfscr & HFSCR_TM) {
 			vcpu->arch.texasr = mfspr(SPRN_TEXASR);
 			vcpu->arch.tfhar = mfspr(SPRN_TFHAR);
 			vcpu->arch.tfiar = mfspr(SPRN_TFIAR);
+
+			if (!vcpu->arch.nested) {
+				vcpu->arch.load_tm++; /* see load_ebb comment */
+				if (!vcpu->arch.load_tm)
+					vcpu->arch.hfscr &= ~HFSCR_TM;
+			}
 		}
 	}
 #endif
@@ -641,8 +647,9 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
 		msr |= MSR_VEC;
 	if (cpu_has_feature(CPU_FTR_VSX))
 		msr |= MSR_VSX;
-	if (cpu_has_feature(CPU_FTR_TM) ||
-	    cpu_has_feature(CPU_FTR_P9_TM_HV_ASSIST))
+	if ((cpu_has_feature(CPU_FTR_TM) ||
+	    cpu_has_feature(CPU_FTR_P9_TM_HV_ASSIST)) &&
+			(vcpu->arch.hfscr & HFSCR_TM))
 		msr |= MSR_TM;
 	msr = msr_check_and_set(msr);
 	/* Save MSR for restore. This is after hard disable, so EE is clear. */
-- 
2.23.0

[PATCH v4 38/53] KVM: PPC: Book3S HV P9: Use Linux SPR save/restore to manage some host SPRs

[Nicholas Piggin]

Linux implements SPR save/restore including storage space for registers
in the task struct for process context switching. Make use of this
similarly to the way we make use of the context switching fp/vec save
restore.

This improves code reuse, allows some stack space to be saved, and helps
with avoiding VRSAVE updates if they are not required.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/include/asm/switch_to.h  |  1 +
 arch/powerpc/kernel/process.c         |  6 ++
 arch/powerpc/kvm/book3s_hv.c          | 21 +-----
 arch/powerpc/kvm/book3s_hv.h          |  3 -
 arch/powerpc/kvm/book3s_hv_p9_entry.c | 93 +++++++++++++++++++--------
 5 files changed, 73 insertions(+), 51 deletions(-)

diff --git a/arch/powerpc/include/asm/switch_to.h b/arch/powerpc/include/asm/switch_to.h
index e8013cd6b646..1f43ef696033 100644
--- a/arch/powerpc/include/asm/switch_to.h
+++ b/arch/powerpc/include/asm/switch_to.h
@@ -113,6 +113,7 @@ static inline void clear_task_ebb(struct task_struct *t)
 }
 
 void kvmppc_save_user_regs(void);
+void kvmppc_save_current_sprs(void);
 
 extern int set_thread_tidr(struct task_struct *t);
 
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index 8f841fbe16ad..5d2333d2a283 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -1182,6 +1182,12 @@ void kvmppc_save_user_regs(void)
 #endif
 }
 EXPORT_SYMBOL_GPL(kvmppc_save_user_regs);
+
+void kvmppc_save_current_sprs(void)
+{
+	save_sprs(&current->thread);
+}
+EXPORT_SYMBOL_GPL(kvmppc_save_current_sprs);
 #endif /* CONFIG_KVM_BOOK3S_HV_POSSIBLE */
 
 static inline void restore_sprs(struct thread_struct *old_thread,
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 198f6d997330..7d48aa8aebb2 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -4566,9 +4566,6 @@ static int kvmppc_vcpu_run_hv(struct kvm_vcpu *vcpu)
 	struct kvm_run *run = vcpu->run;
 	int r;
 	int srcu_idx;
-	unsigned long ebb_regs[3] = {};	/* shut up GCC */
-	unsigned long user_tar = 0;
-	unsigned int user_vrsave;
 	struct kvm *kvm;
 	unsigned long msr;
 
@@ -4629,14 +4626,7 @@ static int kvmppc_vcpu_run_hv(struct kvm_vcpu *vcpu)
 
 	kvmppc_save_user_regs();
 
-	/* Save userspace EBB and other register values */
-	if (cpu_has_feature(CPU_FTR_ARCH_207S)) {
-		ebb_regs[0] = mfspr(SPRN_EBBHR);
-		ebb_regs[1] = mfspr(SPRN_EBBRR);
-		ebb_regs[2] = mfspr(SPRN_BESCR);
-		user_tar = mfspr(SPRN_TAR);
-	}
-	user_vrsave = mfspr(SPRN_VRSAVE);
+	kvmppc_save_current_sprs();
 
 	vcpu->arch.waitp = &vcpu->arch.vcore->wait;
 	vcpu->arch.pgdir = kvm->mm->pgd;
@@ -4677,15 +4667,6 @@ static int kvmppc_vcpu_run_hv(struct kvm_vcpu *vcpu)
 		}
 	} while (is_kvmppc_resume_guest(r));
 
-	/* Restore userspace EBB and other register values */
-	if (cpu_has_feature(CPU_FTR_ARCH_207S)) {
-		mtspr(SPRN_EBBHR, ebb_regs[0]);
-		mtspr(SPRN_EBBRR, ebb_regs[1]);
-		mtspr(SPRN_BESCR, ebb_regs[2]);
-		mtspr(SPRN_TAR, user_tar);
-	}
-	mtspr(SPRN_VRSAVE, user_vrsave);
-
 	vcpu->arch.state = KVMPPC_VCPU_NOTREADY;
 	atomic_dec(&kvm->arch.vcpus_running);
 
diff --git a/arch/powerpc/kvm/book3s_hv.h b/arch/powerpc/kvm/book3s_hv.h
index d7485b9e9762..6b7f07d9026b 100644
--- a/arch/powerpc/kvm/book3s_hv.h
+++ b/arch/powerpc/kvm/book3s_hv.h
@@ -4,11 +4,8 @@
  * Privileged (non-hypervisor) host registers to save.
  */
 struct p9_host_os_sprs {
-	unsigned long dscr;
-	unsigned long tidr;
 	unsigned long iamr;
 	unsigned long amr;
-	unsigned long fscr;
 
 	unsigned int pmc1;
 	unsigned int pmc2;
diff --git a/arch/powerpc/kvm/book3s_hv_p9_entry.c b/arch/powerpc/kvm/book3s_hv_p9_entry.c
index 8499e8a9ca8f..093ac0453d91 100644
--- a/arch/powerpc/kvm/book3s_hv_p9_entry.c
+++ b/arch/powerpc/kvm/book3s_hv_p9_entry.c
@@ -231,15 +231,26 @@ EXPORT_SYMBOL_GPL(switch_pmu_to_host);
 static void load_spr_state(struct kvm_vcpu *vcpu,
 				struct p9_host_os_sprs *host_os_sprs)
 {
+	/* TAR is very fast */
 	mtspr(SPRN_TAR, vcpu->arch.tar);
 
+#ifdef CONFIG_ALTIVEC
+	if (cpu_has_feature(CPU_FTR_ALTIVEC) &&
+	    current->thread.vrsave != vcpu->arch.vrsave)
+		mtspr(SPRN_VRSAVE, vcpu->arch.vrsave);
+#endif
+
 	if (vcpu->arch.hfscr & HFSCR_EBB) {
-		mtspr(SPRN_EBBHR, vcpu->arch.ebbhr);
-		mtspr(SPRN_EBBRR, vcpu->arch.ebbrr);
-		mtspr(SPRN_BESCR, vcpu->arch.bescr);
+		if (current->thread.ebbhr != vcpu->arch.ebbhr)
+			mtspr(SPRN_EBBHR, vcpu->arch.ebbhr);
+		if (current->thread.ebbrr != vcpu->arch.ebbrr)
+			mtspr(SPRN_EBBRR, vcpu->arch.ebbrr);
+		if (current->thread.bescr != vcpu->arch.bescr)
+			mtspr(SPRN_BESCR, vcpu->arch.bescr);
 	}
 
-	if (cpu_has_feature(CPU_FTR_P9_TIDR))
+	if (cpu_has_feature(CPU_FTR_P9_TIDR) &&
+			current->thread.tidr != vcpu->arch.tid)
 		mtspr(SPRN_TIDR, vcpu->arch.tid);
 	if (host_os_sprs->iamr != vcpu->arch.iamr)
 		mtspr(SPRN_IAMR, vcpu->arch.iamr);
@@ -247,9 +258,9 @@ static void load_spr_state(struct kvm_vcpu *vcpu,
 		mtspr(SPRN_AMR, vcpu->arch.amr);
 	if (vcpu->arch.uamor != 0)
 		mtspr(SPRN_UAMOR, vcpu->arch.uamor);
-	if (host_os_sprs->fscr != vcpu->arch.fscr)
+	if (current->thread.fscr != vcpu->arch.fscr)
 		mtspr(SPRN_FSCR, vcpu->arch.fscr);
-	if (host_os_sprs->dscr != vcpu->arch.dscr)
+	if (current->thread.dscr != vcpu->arch.dscr)
 		mtspr(SPRN_DSCR, vcpu->arch.dscr);
 	if (vcpu->arch.pspb != 0)
 		mtspr(SPRN_PSPB, vcpu->arch.pspb);
@@ -269,20 +280,15 @@ static void store_spr_state(struct kvm_vcpu *vcpu)
 {
 	vcpu->arch.tar = mfspr(SPRN_TAR);
 
+#ifdef CONFIG_ALTIVEC
+	if (cpu_has_feature(CPU_FTR_ALTIVEC))
+		vcpu->arch.vrsave = mfspr(SPRN_VRSAVE);
+#endif
+
 	if (vcpu->arch.hfscr & HFSCR_EBB) {
 		vcpu->arch.ebbhr = mfspr(SPRN_EBBHR);
 		vcpu->arch.ebbrr = mfspr(SPRN_EBBRR);
 		vcpu->arch.bescr = mfspr(SPRN_BESCR);
-		/*
-		 * This is like load_fp in context switching, turn off the
-		 * facility after it wraps the u8 to try avoiding saving
-		 * and restoring the registers each partition switch.
-		 */
-		if (!vcpu->arch.nested) {
-			vcpu->arch.load_ebb++;
-			if (!vcpu->arch.load_ebb)
-				vcpu->arch.hfscr &= ~HFSCR_EBB;
-		}
 	}
 
 	if (cpu_has_feature(CPU_FTR_P9_TIDR))
@@ -324,7 +330,6 @@ bool load_vcpu_state(struct kvm_vcpu *vcpu,
 #ifdef CONFIG_ALTIVEC
 	load_vr_state(&vcpu->arch.vr);
 #endif
-	mtspr(SPRN_VRSAVE, vcpu->arch.vrsave);
 
 	return ret;
 }
@@ -338,7 +343,6 @@ void store_vcpu_state(struct kvm_vcpu *vcpu)
 #ifdef CONFIG_ALTIVEC
 	store_vr_state(&vcpu->arch.vr);
 #endif
-	vcpu->arch.vrsave = mfspr(SPRN_VRSAVE);
 
 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
 	if (cpu_has_feature(CPU_FTR_TM) ||
@@ -364,12 +368,8 @@ EXPORT_SYMBOL_GPL(store_vcpu_state);
 
 void save_p9_host_os_sprs(struct p9_host_os_sprs *host_os_sprs)
 {
-	if (cpu_has_feature(CPU_FTR_P9_TIDR))
-		host_os_sprs->tidr = mfspr(SPRN_TIDR);
 	host_os_sprs->iamr = mfspr(SPRN_IAMR);
 	host_os_sprs->amr = mfspr(SPRN_AMR);
-	host_os_sprs->fscr = mfspr(SPRN_FSCR);
-	host_os_sprs->dscr = mfspr(SPRN_DSCR);
 }
 EXPORT_SYMBOL_GPL(save_p9_host_os_sprs);
 
@@ -377,26 +377,63 @@ EXPORT_SYMBOL_GPL(save_p9_host_os_sprs);
 void restore_p9_host_os_sprs(struct kvm_vcpu *vcpu,
 			     struct p9_host_os_sprs *host_os_sprs)
 {
+	/*
+	 * current->thread.xxx registers must all be restored to host
+	 * values before a potential context switch, othrewise the context
+	 * switch itself will overwrite current->thread.xxx with the values
+	 * from the guest SPRs.
+	 */
+
 	mtspr(SPRN_SPRG_VDSO_WRITE, local_paca->sprg_vdso);
 
-	if (cpu_has_feature(CPU_FTR_P9_TIDR))
-		mtspr(SPRN_TIDR, host_os_sprs->tidr);
+	if (cpu_has_feature(CPU_FTR_P9_TIDR) &&
+			current->thread.tidr != vcpu->arch.tid)
+		mtspr(SPRN_TIDR, current->thread.tidr);
 	if (host_os_sprs->iamr != vcpu->arch.iamr)
 		mtspr(SPRN_IAMR, host_os_sprs->iamr);
 	if (vcpu->arch.uamor != 0)
 		mtspr(SPRN_UAMOR, 0);
 	if (host_os_sprs->amr != vcpu->arch.amr)
 		mtspr(SPRN_AMR, host_os_sprs->amr);
-	if (host_os_sprs->fscr != vcpu->arch.fscr)
-		mtspr(SPRN_FSCR, host_os_sprs->fscr);
-	if (host_os_sprs->dscr != vcpu->arch.dscr)
-		mtspr(SPRN_DSCR, host_os_sprs->dscr);
+	if (current->thread.fscr != vcpu->arch.fscr)
+		mtspr(SPRN_FSCR, current->thread.fscr);
+	if (current->thread.dscr != vcpu->arch.dscr)
+		mtspr(SPRN_DSCR, current->thread.dscr);
 	if (vcpu->arch.pspb != 0)
 		mtspr(SPRN_PSPB, 0);
 
 	/* Save guest CTRL register, set runlatch to 1 */
 	if (!(vcpu->arch.ctrl & 1))
 		mtspr(SPRN_CTRLT, 1);
+
+#ifdef CONFIG_ALTIVEC
+	if (cpu_has_feature(CPU_FTR_ALTIVEC) &&
+	    vcpu->arch.vrsave != current->thread.vrsave)
+		mtspr(SPRN_VRSAVE, current->thread.vrsave);
+#endif
+	if (vcpu->arch.hfscr & HFSCR_EBB) {
+		if (vcpu->arch.bescr != current->thread.bescr)
+			mtspr(SPRN_BESCR, current->thread.bescr);
+		if (vcpu->arch.ebbhr != current->thread.ebbhr)
+			mtspr(SPRN_EBBHR, current->thread.ebbhr);
+		if (vcpu->arch.ebbrr != current->thread.ebbrr)
+			mtspr(SPRN_EBBRR, current->thread.ebbrr);
+
+		if (!vcpu->arch.nested) {
+			/*
+			 * This is like load_fp in context switching, turn off
+			 * the facility after it wraps the u8 to try avoiding
+			 * saving and restoring the registers each partition
+			 * switch.
+			 */
+			vcpu->arch.load_ebb++;
+			if (!vcpu->arch.load_ebb)
+				vcpu->arch.hfscr &= ~HFSCR_EBB;
+		}
+	}
+
+	if (vcpu->arch.tar != current->thread.tar)
+		mtspr(SPRN_TAR, current->thread.tar);
 }
 EXPORT_SYMBOL_GPL(restore_p9_host_os_sprs);
 
-- 
2.23.0

[PATCH v4 39/53] KVM: PPC: Book3S HV P9: Comment and fix MMU context switching code

[Nicholas Piggin]

Tighten up partition switching code synchronisation and comments.

In particular, hwsync ; isync is required after the last access that is
performed in the context of a partition, before the partition is
switched away from.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/kvm/book3s_64_entry.S     | 11 +++++--
 arch/powerpc/kvm/book3s_64_mmu_radix.c |  4 +++
 arch/powerpc/kvm/book3s_hv_p9_entry.c  | 40 +++++++++++++++++++-------
 3 files changed, 42 insertions(+), 13 deletions(-)

diff --git a/arch/powerpc/kvm/book3s_64_entry.S b/arch/powerpc/kvm/book3s_64_entry.S
index 983b8c18bc31..05e003eb5d90 100644
--- a/arch/powerpc/kvm/book3s_64_entry.S
+++ b/arch/powerpc/kvm/book3s_64_entry.S
@@ -374,11 +374,16 @@ END_MMU_FTR_SECTION_IFCLR(MMU_FTR_TYPE_RADIX)
 BEGIN_FTR_SECTION
 	mtspr	SPRN_DAWRX1,r10
 END_FTR_SECTION_IFSET(CPU_FTR_DAWR1)
-	mtspr	SPRN_PID,r10
 
 	/*
-	 * Switch to host MMU mode
+	 * Switch to host MMU mode (don't have the real host PID but we aren't
+	 * going back to userspace).
 	 */
+	hwsync
+	isync
+
+	mtspr	SPRN_PID,r10
+
 	ld	r10, HSTATE_KVM_VCPU(r13)
 	ld	r10, VCPU_KVM(r10)
 	lwz	r10, KVM_HOST_LPID(r10)
@@ -389,6 +394,8 @@ END_FTR_SECTION_IFSET(CPU_FTR_DAWR1)
 	ld	r10, KVM_HOST_LPCR(r10)
 	mtspr	SPRN_LPCR,r10
 
+	isync
+
 	/*
 	 * Set GUEST_MODE_NONE so the handler won't branch to KVM, and clear
 	 * MSR_RI in r12 ([H]SRR1) so the handler won't try to return.
diff --git a/arch/powerpc/kvm/book3s_64_mmu_radix.c b/arch/powerpc/kvm/book3s_64_mmu_radix.c
index 16359525a40f..8cebe5542256 100644
--- a/arch/powerpc/kvm/book3s_64_mmu_radix.c
+++ b/arch/powerpc/kvm/book3s_64_mmu_radix.c
@@ -57,6 +57,8 @@ unsigned long __kvmhv_copy_tofrom_guest_radix(int lpid, int pid,
 
 	preempt_disable();
 
+	asm volatile("hwsync" ::: "memory");
+	isync();
 	/* switch the lpid first to avoid running host with unallocated pid */
 	old_lpid = mfspr(SPRN_LPID);
 	if (old_lpid != lpid)
@@ -75,6 +77,8 @@ unsigned long __kvmhv_copy_tofrom_guest_radix(int lpid, int pid,
 		ret = __copy_to_user_inatomic((void __user *)to, from, n);
 	pagefault_enable();
 
+	asm volatile("hwsync" ::: "memory");
+	isync();
 	/* switch the pid first to avoid running host with unallocated pid */
 	if (quadrant == 1 && pid != old_pid)
 		mtspr(SPRN_PID, old_pid);
diff --git a/arch/powerpc/kvm/book3s_hv_p9_entry.c b/arch/powerpc/kvm/book3s_hv_p9_entry.c
index 093ac0453d91..323b692bbfe2 100644
--- a/arch/powerpc/kvm/book3s_hv_p9_entry.c
+++ b/arch/powerpc/kvm/book3s_hv_p9_entry.c
@@ -531,17 +531,19 @@ static void switch_mmu_to_guest_radix(struct kvm *kvm, struct kvm_vcpu *vcpu, u6
 	lpid = nested ? nested->shadow_lpid : kvm->arch.lpid;
 
 	/*
-	 * All the isync()s are overkill but trivially follow the ISA
-	 * requirements. Some can likely be replaced with justification
-	 * comment for why they are not needed.
+	 * Prior memory accesses to host PID Q3 must be completed before we
+	 * start switching, and stores must be drained to avoid not-my-LPAR
+	 * logic (see switch_mmu_to_host).
 	 */
+	asm volatile("hwsync" ::: "memory");
 	isync();
 	mtspr(SPRN_LPID, lpid);
-	isync();
 	mtspr(SPRN_LPCR, lpcr);
-	isync();
 	mtspr(SPRN_PID, vcpu->arch.pid);
-	isync();
+	/*
+	 * isync not required here because we are HRFID'ing to guest before
+	 * any guest context access, which is context synchronising.
+	 */
 }
 
 static void switch_mmu_to_guest_hpt(struct kvm *kvm, struct kvm_vcpu *vcpu, u64 lpcr)
@@ -551,25 +553,41 @@ static void switch_mmu_to_guest_hpt(struct kvm *kvm, struct kvm_vcpu *vcpu, u64
 
 	lpid = kvm->arch.lpid;
 
+	/*
+	 * See switch_mmu_to_guest_radix. ptesync should not be required here
+	 * even if the host is in HPT mode because speculative accesses would
+	 * not cause RC updates (we are in real mode).
+	 */
+	asm volatile("hwsync" ::: "memory");
+	isync();
 	mtspr(SPRN_LPID, lpid);
 	mtspr(SPRN_LPCR, lpcr);
 	mtspr(SPRN_PID, vcpu->arch.pid);
 
 	for (i = 0; i < vcpu->arch.slb_max; i++)
 		mtslb(vcpu->arch.slb[i].orige, vcpu->arch.slb[i].origv);
-
-	isync();
+	/*
+	 * isync not required here, see switch_mmu_to_guest_radix.
+	 */
 }
 
 static void switch_mmu_to_host(struct kvm *kvm, u32 pid)
 {
+	/*
+	 * The guest has exited, so guest MMU context is no longer being
+	 * non-speculatively accessed, but a hwsync is needed before the
+	 * mtLPIDR / mtPIDR switch, in order to ensure all stores are drained,
+	 * so the not-my-LPAR tlbie logic does not overlook them.
+	 */
+	asm volatile("hwsync" ::: "memory");
 	isync();
 	mtspr(SPRN_PID, pid);
-	isync();
 	mtspr(SPRN_LPID, kvm->arch.host_lpid);
-	isync();
 	mtspr(SPRN_LPCR, kvm->arch.host_lpcr);
-	isync();
+	/*
+	 * isync is not required after the switch, because mtmsrd with L=0
+	 * is performed after this switch, which is context synchronising.
+	 */
 
 	if (!radix_enabled())
 		slb_restore_bolted_realmode();
-- 
2.23.0

[PATCH v4 40/53] KVM: PPC: Book3S HV P9: Test dawr_enabled() before saving host DAWR SPRs

[Nicholas Piggin]

Some of the DAWR SPR access is already predicated on dawr_enabled(),
apply this to the remainder of the accesses.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/kvm/book3s_hv_p9_entry.c | 34 ++++++++++++++++-----------
 1 file changed, 20 insertions(+), 14 deletions(-)

diff --git a/arch/powerpc/kvm/book3s_hv_p9_entry.c b/arch/powerpc/kvm/book3s_hv_p9_entry.c
index 323b692bbfe2..0f341011816c 100644
--- a/arch/powerpc/kvm/book3s_hv_p9_entry.c
+++ b/arch/powerpc/kvm/book3s_hv_p9_entry.c
@@ -666,13 +666,16 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
 
 	host_hfscr = mfspr(SPRN_HFSCR);
 	host_ciabr = mfspr(SPRN_CIABR);
-	host_dawr0 = mfspr(SPRN_DAWR0);
-	host_dawrx0 = mfspr(SPRN_DAWRX0);
 	host_psscr = mfspr(SPRN_PSSCR);
 	host_pidr = mfspr(SPRN_PID);
-	if (cpu_has_feature(CPU_FTR_DAWR1)) {
-		host_dawr1 = mfspr(SPRN_DAWR1);
-		host_dawrx1 = mfspr(SPRN_DAWRX1);
+
+	if (dawr_enabled()) {
+		host_dawr0 = mfspr(SPRN_DAWR0);
+		host_dawrx0 = mfspr(SPRN_DAWRX0);
+		if (cpu_has_feature(CPU_FTR_DAWR1)) {
+			host_dawr1 = mfspr(SPRN_DAWR1);
+			host_dawrx1 = mfspr(SPRN_DAWRX1);
+		}
 	}
 
 	local_paca->kvm_hstate.host_purr = mfspr(SPRN_PURR);
@@ -1006,15 +1009,18 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
 	mtspr(SPRN_HFSCR, host_hfscr);
 	if (vcpu->arch.ciabr != host_ciabr)
 		mtspr(SPRN_CIABR, host_ciabr);
-	if (vcpu->arch.dawr0 != host_dawr0)
-		mtspr(SPRN_DAWR0, host_dawr0);
-	if (vcpu->arch.dawrx0 != host_dawrx0)
-		mtspr(SPRN_DAWRX0, host_dawrx0);
-	if (cpu_has_feature(CPU_FTR_DAWR1)) {
-		if (vcpu->arch.dawr1 != host_dawr1)
-			mtspr(SPRN_DAWR1, host_dawr1);
-		if (vcpu->arch.dawrx1 != host_dawrx1)
-			mtspr(SPRN_DAWRX1, host_dawrx1);
+
+	if (dawr_enabled()) {
+		if (vcpu->arch.dawr0 != host_dawr0)
+			mtspr(SPRN_DAWR0, host_dawr0);
+		if (vcpu->arch.dawrx0 != host_dawrx0)
+			mtspr(SPRN_DAWRX0, host_dawrx0);
+		if (cpu_has_feature(CPU_FTR_DAWR1)) {
+			if (vcpu->arch.dawr1 != host_dawr1)
+				mtspr(SPRN_DAWR1, host_dawr1);
+			if (vcpu->arch.dawrx1 != host_dawrx1)
+				mtspr(SPRN_DAWRX1, host_dawrx1);
+		}
 	}
 
 	if (vc->dpdes)
-- 
2.23.0

[PATCH v4 41/53] KVM: PPC: Book3S HV P9: Don't restore PSSCR if not needed

[Nicholas Piggin]

This also moves the PSSCR update in nested entry to avoid a SPR
scoreboard stall.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/kvm/book3s_hv.c          |  7 +++++--
 arch/powerpc/kvm/book3s_hv_p9_entry.c | 26 +++++++++++++++++++-------
 2 files changed, 24 insertions(+), 9 deletions(-)

diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 7d48aa8aebb2..9da27f19a697 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -3889,7 +3889,9 @@ static int kvmhv_vcpu_entry_p9_nested(struct kvm_vcpu *vcpu, u64 time_limit, uns
 	if (unlikely(load_vcpu_state(vcpu, &host_os_sprs)))
 		msr = mfmsr(); /* TM restore can update msr */
 
-	mtspr(SPRN_PSSCR_PR, vcpu->arch.psscr);
+	if (vcpu->arch.psscr != host_psscr)
+		mtspr(SPRN_PSSCR_PR, vcpu->arch.psscr);
+
 	kvmhv_save_hv_regs(vcpu, &hvregs);
 	hvregs.lpcr = lpcr;
 	vcpu->arch.regs.msr = vcpu->arch.shregs.msr;
@@ -3930,7 +3932,6 @@ static int kvmhv_vcpu_entry_p9_nested(struct kvm_vcpu *vcpu, u64 time_limit, uns
 	vcpu->arch.shregs.dar = mfspr(SPRN_DAR);
 	vcpu->arch.shregs.dsisr = mfspr(SPRN_DSISR);
 	vcpu->arch.psscr = mfspr(SPRN_PSSCR_PR);
-	mtspr(SPRN_PSSCR_PR, host_psscr);
 
 	store_vcpu_state(vcpu);
 
@@ -3943,6 +3944,8 @@ static int kvmhv_vcpu_entry_p9_nested(struct kvm_vcpu *vcpu, u64 time_limit, uns
 	timer_rearm_host_dec(*tb);
 
 	restore_p9_host_os_sprs(vcpu, &host_os_sprs);
+	if (vcpu->arch.psscr != host_psscr)
+		mtspr(SPRN_PSSCR_PR, host_psscr);
 
 	return trap;
 }
diff --git a/arch/powerpc/kvm/book3s_hv_p9_entry.c b/arch/powerpc/kvm/book3s_hv_p9_entry.c
index 0f341011816c..eae9d806d704 100644
--- a/arch/powerpc/kvm/book3s_hv_p9_entry.c
+++ b/arch/powerpc/kvm/book3s_hv_p9_entry.c
@@ -649,6 +649,7 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
 	unsigned long host_dawr0;
 	unsigned long host_dawrx0;
 	unsigned long host_psscr;
+	unsigned long host_hpsscr;
 	unsigned long host_pidr;
 	unsigned long host_dawr1;
 	unsigned long host_dawrx1;
@@ -666,7 +667,9 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
 
 	host_hfscr = mfspr(SPRN_HFSCR);
 	host_ciabr = mfspr(SPRN_CIABR);
-	host_psscr = mfspr(SPRN_PSSCR);
+	host_psscr = mfspr(SPRN_PSSCR_PR);
+	if (cpu_has_feature(CPU_FTR_P9_TM_HV_ASSIST))
+		host_hpsscr = mfspr(SPRN_PSSCR);
 	host_pidr = mfspr(SPRN_PID);
 
 	if (dawr_enabled()) {
@@ -750,8 +753,14 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
 	if (vcpu->arch.ciabr != host_ciabr)
 		mtspr(SPRN_CIABR, vcpu->arch.ciabr);
 
-	mtspr(SPRN_PSSCR, vcpu->arch.psscr | PSSCR_EC |
-	      (local_paca->kvm_hstate.fake_suspend << PSSCR_FAKE_SUSPEND_LG));
+
+	if (cpu_has_feature(CPU_FTR_P9_TM_HV_ASSIST)) {
+		mtspr(SPRN_PSSCR, vcpu->arch.psscr | PSSCR_EC |
+		      (local_paca->kvm_hstate.fake_suspend << PSSCR_FAKE_SUSPEND_LG));
+	} else {
+		if (vcpu->arch.psscr != host_psscr)
+			mtspr(SPRN_PSSCR_PR, vcpu->arch.psscr);
+	}
 
 	mtspr(SPRN_HFSCR, vcpu->arch.hfscr);
 
@@ -957,7 +966,7 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
 
 	vcpu->arch.ic = mfspr(SPRN_IC);
 	vcpu->arch.pid = mfspr(SPRN_PID);
-	vcpu->arch.psscr = mfspr(SPRN_PSSCR) & PSSCR_GUEST_VIS;
+	vcpu->arch.psscr = mfspr(SPRN_PSSCR_PR);
 
 	vcpu->arch.shregs.sprg0 = mfspr(SPRN_SPRG0);
 	vcpu->arch.shregs.sprg1 = mfspr(SPRN_SPRG1);
@@ -1003,9 +1012,12 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
 	mtspr(SPRN_PURR, local_paca->kvm_hstate.host_purr);
 	mtspr(SPRN_SPURR, local_paca->kvm_hstate.host_spurr);
 
-	/* Preserve PSSCR[FAKE_SUSPEND] until we've called kvmppc_save_tm_hv */
-	mtspr(SPRN_PSSCR, host_psscr |
-	      (local_paca->kvm_hstate.fake_suspend << PSSCR_FAKE_SUSPEND_LG));
+	if (cpu_has_feature(CPU_FTR_P9_TM_HV_ASSIST)) {
+		/* Preserve PSSCR[FAKE_SUSPEND] until we've called kvmppc_save_tm_hv */
+		mtspr(SPRN_PSSCR, host_hpsscr |
+		      (local_paca->kvm_hstate.fake_suspend << PSSCR_FAKE_SUSPEND_LG));
+	}
+
 	mtspr(SPRN_HFSCR, host_hfscr);
 	if (vcpu->arch.ciabr != host_ciabr)
 		mtspr(SPRN_CIABR, host_ciabr);
-- 
2.23.0

[PATCH v4 42/53] KVM: PPC: Book3S HV: Split P8 from P9 path guest vCPU TLB flushing

[Nicholas Piggin]

This creates separate functions for old and new paths for vCPU TLB
flushing, which will reduce complexity of the next change.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/include/asm/kvm_ppc.h    |  3 +-
 arch/powerpc/kvm/book3s_hv_builtin.c  | 53 ++++-------------------
 arch/powerpc/kvm/book3s_hv_p9_entry.c | 62 ++++++++++++++++++++++++++-
 3 files changed, 70 insertions(+), 48 deletions(-)

diff --git a/arch/powerpc/include/asm/kvm_ppc.h b/arch/powerpc/include/asm/kvm_ppc.h
index 671fbd1a765e..2b76d51e4b13 100644
--- a/arch/powerpc/include/asm/kvm_ppc.h
+++ b/arch/powerpc/include/asm/kvm_ppc.h
@@ -552,8 +552,7 @@ extern void kvm_hv_vm_activated(void);
 extern void kvm_hv_vm_deactivated(void);
 extern bool kvm_hv_mode_active(void);
 
-extern void kvmppc_check_need_tlb_flush(struct kvm *kvm, int pcpu,
-					struct kvm_nested_guest *nested);
+extern void kvmppc_check_need_tlb_flush(struct kvm *kvm, int pcpu);
 
 #else
 static inline void __init kvm_cma_reserve(void)
diff --git a/arch/powerpc/kvm/book3s_hv_builtin.c b/arch/powerpc/kvm/book3s_hv_builtin.c
index 70b7a8f97153..ad70756a777c 100644
--- a/arch/powerpc/kvm/book3s_hv_builtin.c
+++ b/arch/powerpc/kvm/book3s_hv_builtin.c
@@ -682,60 +682,23 @@ static void flush_guest_tlb(struct kvm *kvm)
 	unsigned long rb, set;
 
 	rb = PPC_BIT(52);	/* IS = 2 */
-	if (kvm_is_radix(kvm)) {
-		/* R=1 PRS=1 RIC=2 */
+	for (set = 0; set < kvm->arch.tlb_sets; ++set) {
+		/* R=0 PRS=0 RIC=0 */
 		asm volatile(PPC_TLBIEL(%0, %4, %3, %2, %1)
-			     : : "r" (rb), "i" (1), "i" (1), "i" (2),
+			     : : "r" (rb), "i" (0), "i" (0), "i" (0),
 			       "r" (0) : "memory");
-		for (set = 1; set < kvm->arch.tlb_sets; ++set) {
-			rb += PPC_BIT(51);	/* increment set number */
-			/* R=1 PRS=1 RIC=0 */
-			asm volatile(PPC_TLBIEL(%0, %4, %3, %2, %1)
-				     : : "r" (rb), "i" (1), "i" (1), "i" (0),
-				       "r" (0) : "memory");
-		}
-		asm volatile("ptesync": : :"memory");
-		// POWER9 congruence-class TLBIEL leaves ERAT. Flush it now.
-		asm volatile(PPC_RADIX_INVALIDATE_ERAT_GUEST : : :"memory");
-	} else {
-		for (set = 0; set < kvm->arch.tlb_sets; ++set) {
-			/* R=0 PRS=0 RIC=0 */
-			asm volatile(PPC_TLBIEL(%0, %4, %3, %2, %1)
-				     : : "r" (rb), "i" (0), "i" (0), "i" (0),
-				       "r" (0) : "memory");
-			rb += PPC_BIT(51);	/* increment set number */
-		}
-		asm volatile("ptesync": : :"memory");
-		// POWER9 congruence-class TLBIEL leaves ERAT. Flush it now.
-		if (cpu_has_feature(CPU_FTR_ARCH_300))
-			asm volatile(PPC_ISA_3_0_INVALIDATE_ERAT : : :"memory");
+		rb += PPC_BIT(51);	/* increment set number */
 	}
+	asm volatile("ptesync": : :"memory");
 }
 
-void kvmppc_check_need_tlb_flush(struct kvm *kvm, int pcpu,
-				 struct kvm_nested_guest *nested)
+void kvmppc_check_need_tlb_flush(struct kvm *kvm, int pcpu)
 {
-	cpumask_t *need_tlb_flush;
-
-	/*
-	 * On POWER9, individual threads can come in here, but the
-	 * TLB is shared between the 4 threads in a core, hence
-	 * invalidating on one thread invalidates for all.
-	 * Thus we make all 4 threads use the same bit.
-	 */
-	if (cpu_has_feature(CPU_FTR_ARCH_300))
-		pcpu = cpu_first_tlb_thread_sibling(pcpu);
-
-	if (nested)
-		need_tlb_flush = &nested->need_tlb_flush;
-	else
-		need_tlb_flush = &kvm->arch.need_tlb_flush;
-
-	if (cpumask_test_cpu(pcpu, need_tlb_flush)) {
+	if (cpumask_test_cpu(pcpu, &kvm->arch.need_tlb_flush)) {
 		flush_guest_tlb(kvm);
 
 		/* Clear the bit after the TLB flush */
-		cpumask_clear_cpu(pcpu, need_tlb_flush);
+		cpumask_clear_cpu(pcpu, &kvm->arch.need_tlb_flush);
 	}
 }
 EXPORT_SYMBOL_GPL(kvmppc_check_need_tlb_flush);
diff --git a/arch/powerpc/kvm/book3s_hv_p9_entry.c b/arch/powerpc/kvm/book3s_hv_p9_entry.c
index eae9d806d704..d0216d32ec91 100644
--- a/arch/powerpc/kvm/book3s_hv_p9_entry.c
+++ b/arch/powerpc/kvm/book3s_hv_p9_entry.c
@@ -632,6 +632,66 @@ static void save_clear_guest_mmu(struct kvm *kvm, struct kvm_vcpu *vcpu)
 	}
 }
 
+static void flush_guest_tlb(struct kvm *kvm)
+{
+	unsigned long rb, set;
+
+	rb = PPC_BIT(52);	/* IS = 2 */
+	if (kvm_is_radix(kvm)) {
+		/* R=1 PRS=1 RIC=2 */
+		asm volatile(PPC_TLBIEL(%0, %4, %3, %2, %1)
+			     : : "r" (rb), "i" (1), "i" (1), "i" (2),
+			       "r" (0) : "memory");
+		for (set = 1; set < kvm->arch.tlb_sets; ++set) {
+			rb += PPC_BIT(51);	/* increment set number */
+			/* R=1 PRS=1 RIC=0 */
+			asm volatile(PPC_TLBIEL(%0, %4, %3, %2, %1)
+				     : : "r" (rb), "i" (1), "i" (1), "i" (0),
+				       "r" (0) : "memory");
+		}
+		asm volatile("ptesync": : :"memory");
+		// POWER9 congruence-class TLBIEL leaves ERAT. Flush it now.
+		asm volatile(PPC_RADIX_INVALIDATE_ERAT_GUEST : : :"memory");
+	} else {
+		for (set = 0; set < kvm->arch.tlb_sets; ++set) {
+			/* R=0 PRS=0 RIC=0 */
+			asm volatile(PPC_TLBIEL(%0, %4, %3, %2, %1)
+				     : : "r" (rb), "i" (0), "i" (0), "i" (0),
+				       "r" (0) : "memory");
+			rb += PPC_BIT(51);	/* increment set number */
+		}
+		asm volatile("ptesync": : :"memory");
+		// POWER9 congruence-class TLBIEL leaves ERAT. Flush it now.
+		asm volatile(PPC_ISA_3_0_INVALIDATE_ERAT : : :"memory");
+	}
+}
+
+static void check_need_tlb_flush(struct kvm *kvm, int pcpu,
+				 struct kvm_nested_guest *nested)
+{
+	cpumask_t *need_tlb_flush;
+
+	/*
+	 * On POWER9, individual threads can come in here, but the
+	 * TLB is shared between the 4 threads in a core, hence
+	 * invalidating on one thread invalidates for all.
+	 * Thus we make all 4 threads use the same bit.
+	 */
+	pcpu = cpu_first_tlb_thread_sibling(pcpu);
+
+	if (nested)
+		need_tlb_flush = &nested->need_tlb_flush;
+	else
+		need_tlb_flush = &kvm->arch.need_tlb_flush;
+
+	if (cpumask_test_cpu(pcpu, need_tlb_flush)) {
+		flush_guest_tlb(kvm);
+
+		/* Clear the bit after the TLB flush */
+		cpumask_clear_cpu(pcpu, need_tlb_flush);
+	}
+}
+
 int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpcr, u64 *tb)
 {
 	struct p9_host_os_sprs host_os_sprs;
@@ -819,7 +879,7 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
 	}
 
 	/* TLBIEL uses LPID=LPIDR, so run this after setting guest LPID */
-	kvmppc_check_need_tlb_flush(kvm, vc->pcpu, nested);
+	check_need_tlb_flush(kvm, vc->pcpu, nested);
 
 	/*
 	 * P9 suppresses the HDEC exception when LPCR[HDICE] = 0,
-- 
2.23.0

[PATCH v4 43/53] KVM: PPC: Book3S HV P9: Avoid tlbsync sequence on radix guest exit

[Nicholas Piggin]

Use the existing TLB flushing logic to IPI the previous CPU and run the
necessary barriers before running a guest vCPU on a new physical CPU,
to do the necessary radix GTSE barriers for handling the case of an
interrupted guest tlbie sequence.

This requires the vCPU TLB flush sequence that is currently just done
on one thread, to be expanded to ensure the other threads execute a
ptesync, because causing them to exit the guest will no longer cause a
ptesync by itself.

This results in more IPIs than the TLB flush logic requires, but it's
a significant win for common case scheduling when the vCPU remains on
the same physical CPU.

This saves about 520 cycles (nearly 10%) on a guest entry+exit micro
benchmark on a POWER9.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/kvm/book3s_hv.c          | 48 +++++++++++++++++++++------
 arch/powerpc/kvm/book3s_hv_p9_entry.c | 48 +++++++++++++++------------
 arch/powerpc/kvm/book3s_hv_rm_mmu.c   |  6 ----
 3 files changed, 65 insertions(+), 37 deletions(-)

diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 9da27f19a697..df4e3f88398d 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -3002,29 +3002,54 @@ static void kvmppc_release_hwthread(int cpu)
 static void radix_flush_cpu(struct kvm *kvm, int cpu, struct kvm_vcpu *vcpu)
 {
 	struct kvm_nested_guest *nested = vcpu->arch.nested;
-	cpumask_t *cpu_in_guest;
+	cpumask_t *cpu_in_guest, *need_tlb_flush;
 	int i;
 
-	cpu = cpu_first_tlb_thread_sibling(cpu);
 	if (nested) {
-		cpumask_set_cpu(cpu, &nested->need_tlb_flush);
+		need_tlb_flush = &nested->need_tlb_flush;
 		cpu_in_guest = &nested->cpu_in_guest;
 	} else {
-		cpumask_set_cpu(cpu, &kvm->arch.need_tlb_flush);
+		need_tlb_flush = &kvm->arch.need_tlb_flush;
 		cpu_in_guest = &kvm->arch.cpu_in_guest;
 	}
+
+	cpu = cpu_first_tlb_thread_sibling(cpu);
+	for (i = cpu; i <= cpu_last_tlb_thread_sibling(cpu);
+					i += cpu_tlb_thread_sibling_step())
+		cpumask_set_cpu(i, need_tlb_flush);
+
 	/*
 	 * Make sure setting of bit in need_tlb_flush precedes
 	 * testing of cpu_in_guest bits.  The matching barrier on
 	 * the other side is the first smp_mb() in kvmppc_run_core().
 	 */
 	smp_mb();
+
 	for (i = cpu; i <= cpu_last_tlb_thread_sibling(cpu);
 					i += cpu_tlb_thread_sibling_step())
 		if (cpumask_test_cpu(i, cpu_in_guest))
 			smp_call_function_single(i, do_nothing, NULL, 1);
 }
 
+static void do_migrate_away_vcpu(void *arg)
+{
+	struct kvm_vcpu *vcpu = arg;
+	struct kvm *kvm = vcpu->kvm;
+
+	/*
+	 * If the guest has GTSE, it may execute tlbie, so do a eieio; tlbsync;
+	 * ptesync sequence on the old CPU before migrating to a new one, in
+	 * case we interrupted the guest between a tlbie ; eieio ;
+	 * tlbsync; ptesync sequence.
+	 *
+	 * Otherwise, ptesync is sufficient for ordering tlbiel sequences.
+	 */
+	if (kvm->arch.lpcr & LPCR_GTSE)
+		asm volatile("eieio; tlbsync; ptesync");
+	else
+		asm volatile("ptesync");
+}
+
 static void kvmppc_prepare_radix_vcpu(struct kvm_vcpu *vcpu, int pcpu)
 {
 	struct kvm_nested_guest *nested = vcpu->arch.nested;
@@ -3048,14 +3073,17 @@ static void kvmppc_prepare_radix_vcpu(struct kvm_vcpu *vcpu, int pcpu)
 	 * can move around between pcpus.  To cope with this, when
 	 * a vcpu moves from one pcpu to another, we need to tell
 	 * any vcpus running on the same core as this vcpu previously
-	 * ran to flush the TLB.  The TLB is shared between threads,
-	 * so we use a single bit in .need_tlb_flush for all 4 threads.
+	 * ran to flush the TLB.
 	 */
 	if (prev_cpu != pcpu) {
-		if (prev_cpu >= 0 &&
-		    cpu_first_tlb_thread_sibling(prev_cpu) !=
-		    cpu_first_tlb_thread_sibling(pcpu))
-			radix_flush_cpu(kvm, prev_cpu, vcpu);
+		if (prev_cpu >= 0) {
+			if (cpu_first_tlb_thread_sibling(prev_cpu) !=
+			    cpu_first_tlb_thread_sibling(pcpu))
+				radix_flush_cpu(kvm, prev_cpu, vcpu);
+
+			smp_call_function_single(prev_cpu,
+					do_migrate_away_vcpu, vcpu, 1);
+		}
 		if (nested)
 			nested->prev_cpu[vcpu->arch.nested_vcpu_id] = pcpu;
 		else
diff --git a/arch/powerpc/kvm/book3s_hv_p9_entry.c b/arch/powerpc/kvm/book3s_hv_p9_entry.c
index d0216d32ec91..9e899c813803 100644
--- a/arch/powerpc/kvm/book3s_hv_p9_entry.c
+++ b/arch/powerpc/kvm/book3s_hv_p9_entry.c
@@ -670,26 +670,41 @@ static void check_need_tlb_flush(struct kvm *kvm, int pcpu,
 				 struct kvm_nested_guest *nested)
 {
 	cpumask_t *need_tlb_flush;
-
-	/*
-	 * On POWER9, individual threads can come in here, but the
-	 * TLB is shared between the 4 threads in a core, hence
-	 * invalidating on one thread invalidates for all.
-	 * Thus we make all 4 threads use the same bit.
-	 */
-	pcpu = cpu_first_tlb_thread_sibling(pcpu);
+	bool all_set = true;
+	int i;
 
 	if (nested)
 		need_tlb_flush = &nested->need_tlb_flush;
 	else
 		need_tlb_flush = &kvm->arch.need_tlb_flush;
 
-	if (cpumask_test_cpu(pcpu, need_tlb_flush)) {
-		flush_guest_tlb(kvm);
+	if (likely(!cpumask_test_cpu(pcpu, need_tlb_flush)))
+		return;
 
-		/* Clear the bit after the TLB flush */
-		cpumask_clear_cpu(pcpu, need_tlb_flush);
+	/*
+	 * Individual threads can come in here, but the TLB is shared between
+	 * the 4 threads in a core, hence invalidating on one thread
+	 * invalidates for all, so only invalidate the first time (if all bits
+	 * were set.  The others must still execute a ptesync.
+	 *
+	 * If a race occurs and two threads do the TLB flush, that is not a
+	 * problem, just sub-optimal.
+	 */
+	for (i = cpu_first_tlb_thread_sibling(pcpu);
+			i <= cpu_last_tlb_thread_sibling(pcpu);
+			i += cpu_tlb_thread_sibling_step()) {
+		if (!cpumask_test_cpu(i, need_tlb_flush)) {
+			all_set = false;
+			break;
+		}
 	}
+	if (all_set)
+		flush_guest_tlb(kvm);
+	else
+		asm volatile("ptesync" ::: "memory");
+
+	/* Clear the bit after the TLB flush */
+	cpumask_clear_cpu(pcpu, need_tlb_flush);
 }
 
 int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpcr, u64 *tb)
@@ -1109,15 +1124,6 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
 
 	local_paca->kvm_hstate.in_guest = KVM_GUEST_MODE_NONE;
 
-	if (kvm_is_radix(kvm)) {
-		/*
-		 * Since this is radix, do a eieio; tlbsync; ptesync sequence
-		 * in case we interrupted the guest between a tlbie and a
-		 * ptesync.
-		 */
-		asm volatile("eieio; tlbsync; ptesync");
-	}
-
 	/*
 	 * cp_abort is required if the processor supports local copy-paste
 	 * to clear the copy buffer that was under control of the guest.
diff --git a/arch/powerpc/kvm/book3s_hv_rm_mmu.c b/arch/powerpc/kvm/book3s_hv_rm_mmu.c
index 2c1f3c6e72d1..2257fb18cb72 100644
--- a/arch/powerpc/kvm/book3s_hv_rm_mmu.c
+++ b/arch/powerpc/kvm/book3s_hv_rm_mmu.c
@@ -55,12 +55,6 @@ static int global_invalidates(struct kvm *kvm)
 		smp_wmb();
 		cpumask_setall(&kvm->arch.need_tlb_flush);
 		cpu = local_paca->kvm_hstate.kvm_vcore->pcpu;
-		/*
-		 * On POWER9, threads are independent but the TLB is shared,
-		 * so use the bit for the first thread to represent the core.
-		 */
-		if (cpu_has_feature(CPU_FTR_ARCH_300))
-			cpu = cpu_first_tlb_thread_sibling(cpu);
 		cpumask_clear_cpu(cpu, &kvm->arch.need_tlb_flush);
 	}
 
-- 
2.23.0

[PATCH v4 44/53] KVM: PPC: Book3S HV Nested: Avoid extra mftb() in nested entry

[Nicholas Piggin]

mftb() is expensive and one can be avoided on nested guest dispatch.

If the time checking code distinguishes between the L0 timer and the
nested HV timer, then both can be tested in the same place with the
same mftb() value.

This also nicely illustrates the relationship between the L0 and nested
HV timers.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/include/asm/kvm_asm.h  |  1 +
 arch/powerpc/kvm/book3s_hv.c        | 12 ++++++++++++
 arch/powerpc/kvm/book3s_hv_nested.c |  5 -----
 3 files changed, 13 insertions(+), 5 deletions(-)

diff --git a/arch/powerpc/include/asm/kvm_asm.h b/arch/powerpc/include/asm/kvm_asm.h
index fbbf3cec92e9..d68d71987d5c 100644
--- a/arch/powerpc/include/asm/kvm_asm.h
+++ b/arch/powerpc/include/asm/kvm_asm.h
@@ -79,6 +79,7 @@
 #define BOOK3S_INTERRUPT_FP_UNAVAIL	0x800
 #define BOOK3S_INTERRUPT_DECREMENTER	0x900
 #define BOOK3S_INTERRUPT_HV_DECREMENTER	0x980
+#define BOOK3S_INTERRUPT_NESTED_HV_DECREMENTER	0x1980
 #define BOOK3S_INTERRUPT_DOORBELL	0xa00
 #define BOOK3S_INTERRUPT_SYSCALL	0xc00
 #define BOOK3S_INTERRUPT_TRACE		0xd00
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index df4e3f88398d..65c9157579a3 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -1486,6 +1486,10 @@ static int kvmppc_handle_exit_hv(struct kvm_vcpu *vcpu,
 	run->ready_for_interrupt_injection = 1;
 	switch (vcpu->arch.trap) {
 	/* We're good on these - the host merely wanted to get our attention */
+	case BOOK3S_INTERRUPT_NESTED_HV_DECREMENTER:
+		WARN_ON_ONCE(1); /* Should never happen */
+		vcpu->arch.trap = BOOK3S_INTERRUPT_HV_DECREMENTER;
+		fallthrough;
 	case BOOK3S_INTERRUPT_HV_DECREMENTER:
 		vcpu->stat.dec_exits++;
 		r = RESUME_GUEST;
@@ -1814,6 +1818,12 @@ static int kvmppc_handle_nested_exit(struct kvm_vcpu *vcpu)
 		vcpu->stat.ext_intr_exits++;
 		r = RESUME_GUEST;
 		break;
+	/* These need to go to the nested HV */
+	case BOOK3S_INTERRUPT_NESTED_HV_DECREMENTER:
+		vcpu->arch.trap = BOOK3S_INTERRUPT_HV_DECREMENTER;
+		vcpu->stat.dec_exits++;
+		r = RESUME_HOST;
+		break;
 	/* SR/HMI/PMI are HV interrupts that host has handled. Resume guest.*/
 	case BOOK3S_INTERRUPT_HMI:
 	case BOOK3S_INTERRUPT_PERFMON:
@@ -3993,6 +4003,8 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
 		return BOOK3S_INTERRUPT_HV_DECREMENTER;
 	if (next_timer < time_limit)
 		time_limit = next_timer;
+	else if (*tb >= time_limit) /* nested time limit */
+		return BOOK3S_INTERRUPT_NESTED_HV_DECREMENTER;
 
 	vcpu->arch.ceded = 0;
 
diff --git a/arch/powerpc/kvm/book3s_hv_nested.c b/arch/powerpc/kvm/book3s_hv_nested.c
index 7bed0b91245e..e57c08b968c0 100644
--- a/arch/powerpc/kvm/book3s_hv_nested.c
+++ b/arch/powerpc/kvm/book3s_hv_nested.c
@@ -375,11 +375,6 @@ long kvmhv_enter_nested_guest(struct kvm_vcpu *vcpu)
 	vcpu->arch.ret = RESUME_GUEST;
 	vcpu->arch.trap = 0;
 	do {
-		if (mftb() >= hdec_exp) {
-			vcpu->arch.trap = BOOK3S_INTERRUPT_HV_DECREMENTER;
-			r = RESUME_HOST;
-			break;
-		}
 		r = kvmhv_run_single_vcpu(vcpu, hdec_exp, lpcr);
 	} while (is_kvmppc_resume_guest(r));
 
-- 
2.23.0

[PATCH v4 45/53] KVM: PPC: Book3S HV P9: Improve mfmsr performance on entry

[Nicholas Piggin]

Rearrange the MSR saving on entry so it does not follow the mtmsrd to
disable interrupts, avoiding a possible RAW scoreboard stall.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/include/asm/kvm_book3s_64.h |  2 +
 arch/powerpc/kvm/book3s_hv.c             | 18 ++-----
 arch/powerpc/kvm/book3s_hv_p9_entry.c    | 66 +++++++++++++++---------
 3 files changed, 47 insertions(+), 39 deletions(-)

diff --git a/arch/powerpc/include/asm/kvm_book3s_64.h b/arch/powerpc/include/asm/kvm_book3s_64.h
index 0a319ed9c2fd..96f0fda50a07 100644
--- a/arch/powerpc/include/asm/kvm_book3s_64.h
+++ b/arch/powerpc/include/asm/kvm_book3s_64.h
@@ -154,6 +154,8 @@ static inline bool kvmhv_vcpu_is_radix(struct kvm_vcpu *vcpu)
 	return radix;
 }
 
+unsigned long kvmppc_msr_hard_disable_set_facilities(struct kvm_vcpu *vcpu, unsigned long msr);
+
 int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpcr, u64 *tb);
 
 #define KVM_DEFAULT_HPT_ORDER	24	/* 16MB HPT by default */
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 65c9157579a3..e532a7010dba 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -3896,6 +3896,8 @@ static int kvmhv_vcpu_entry_p9_nested(struct kvm_vcpu *vcpu, u64 time_limit, uns
 	s64 dec;
 	int trap;
 
+	msr = mfmsr();
+
 	save_p9_host_os_sprs(&host_os_sprs);
 
 	/*
@@ -3906,24 +3908,10 @@ static int kvmhv_vcpu_entry_p9_nested(struct kvm_vcpu *vcpu, u64 time_limit, uns
 	 */
 	host_psscr = mfspr(SPRN_PSSCR_PR);
 
-	hard_irq_disable();
+	kvmppc_msr_hard_disable_set_facilities(vcpu, msr);
 	if (lazy_irq_pending())
 		return 0;
 
-	/* MSR bits may have been cleared by context switch */
-	msr = 0;
-	if (IS_ENABLED(CONFIG_PPC_FPU))
-		msr |= MSR_FP;
-	if (cpu_has_feature(CPU_FTR_ALTIVEC))
-		msr |= MSR_VEC;
-	if (cpu_has_feature(CPU_FTR_VSX))
-		msr |= MSR_VSX;
-	if ((cpu_has_feature(CPU_FTR_TM) ||
-	    cpu_has_feature(CPU_FTR_P9_TM_HV_ASSIST)) &&
-			(vcpu->arch.hfscr & HFSCR_TM))
-		msr |= MSR_TM;
-	msr = msr_check_and_set(msr);
-
 	if (unlikely(load_vcpu_state(vcpu, &host_os_sprs)))
 		msr = mfmsr(); /* TM restore can update msr */
 
diff --git a/arch/powerpc/kvm/book3s_hv_p9_entry.c b/arch/powerpc/kvm/book3s_hv_p9_entry.c
index 9e899c813803..d123813296ba 100644
--- a/arch/powerpc/kvm/book3s_hv_p9_entry.c
+++ b/arch/powerpc/kvm/book3s_hv_p9_entry.c
@@ -707,6 +707,44 @@ static void check_need_tlb_flush(struct kvm *kvm, int pcpu,
 	cpumask_clear_cpu(pcpu, need_tlb_flush);
 }
 
+unsigned long kvmppc_msr_hard_disable_set_facilities(struct kvm_vcpu *vcpu, unsigned long msr)
+{
+	unsigned long msr_needed = 0;
+
+	msr &= ~MSR_EE;
+
+	/* MSR bits may have been cleared by context switch so must recheck */
+	if (IS_ENABLED(CONFIG_PPC_FPU))
+		msr_needed |= MSR_FP;
+	if (cpu_has_feature(CPU_FTR_ALTIVEC))
+		msr_needed |= MSR_VEC;
+	if (cpu_has_feature(CPU_FTR_VSX))
+		msr_needed |= MSR_VSX;
+	if ((cpu_has_feature(CPU_FTR_TM) ||
+	    cpu_has_feature(CPU_FTR_P9_TM_HV_ASSIST)) &&
+			(vcpu->arch.hfscr & HFSCR_TM))
+		msr_needed |= MSR_TM;
+
+	/*
+	 * This could be combined with MSR[RI] clearing, but that expands
+	 * the unrecoverable window. It would be better to cover unrecoverable
+	 * with KVM bad interrupt handling rather than use MSR[RI] at all.
+	 *
+	 * Much more difficult and less worthwhile to combine with IR/DR
+	 * disable.
+	 */
+	if ((msr & msr_needed) != msr_needed) {
+		msr |= msr_needed;
+		__mtmsrd(msr, 0);
+	} else {
+		__hard_irq_disable();
+	}
+	local_paca->irq_happened |= PACA_IRQ_HARD_DIS;
+
+	return msr;
+}
+EXPORT_SYMBOL_GPL(kvmppc_msr_hard_disable_set_facilities);
+
 int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpcr, u64 *tb)
 {
 	struct p9_host_os_sprs host_os_sprs;
@@ -740,6 +778,9 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
 
 	vcpu->arch.ceded = 0;
 
+	/* Save MSR for restore, with EE clear. */
+	msr = mfmsr() & ~MSR_EE;
+
 	host_hfscr = mfspr(SPRN_HFSCR);
 	host_ciabr = mfspr(SPRN_CIABR);
 	host_psscr = mfspr(SPRN_PSSCR_PR);
@@ -761,35 +802,12 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
 
 	save_p9_host_os_sprs(&host_os_sprs);
 
-	/*
-	 * This could be combined with MSR[RI] clearing, but that expands
-	 * the unrecoverable window. It would be better to cover unrecoverable
-	 * with KVM bad interrupt handling rather than use MSR[RI] at all.
-	 *
-	 * Much more difficult and less worthwhile to combine with IR/DR
-	 * disable.
-	 */
-	hard_irq_disable();
+	msr = kvmppc_msr_hard_disable_set_facilities(vcpu, msr);
 	if (lazy_irq_pending()) {
 		trap = 0;
 		goto out;
 	}
 
-	/* MSR bits may have been cleared by context switch */
-	msr = 0;
-	if (IS_ENABLED(CONFIG_PPC_FPU))
-		msr |= MSR_FP;
-	if (cpu_has_feature(CPU_FTR_ALTIVEC))
-		msr |= MSR_VEC;
-	if (cpu_has_feature(CPU_FTR_VSX))
-		msr |= MSR_VSX;
-	if ((cpu_has_feature(CPU_FTR_TM) ||
-	    cpu_has_feature(CPU_FTR_P9_TM_HV_ASSIST)) &&
-			(vcpu->arch.hfscr & HFSCR_TM))
-		msr |= MSR_TM;
-	msr = msr_check_and_set(msr);
-	/* Save MSR for restore. This is after hard disable, so EE is clear. */
-
 	if (unlikely(load_vcpu_state(vcpu, &host_os_sprs)))
 		msr = mfmsr(); /* MSR may have been updated */
 
-- 
2.23.0

[PATCH v4 46/53] KVM: PPC: Book3S HV P9: Optimise hash guest SLB saving

[Nicholas Piggin]

slbmfee/slbmfev instructions are very expensive, moreso than a regular
mfspr instruction, so minimising them significantly improves hash guest
exit performance. The slbmfev is only required if slbmfee found a valid
SLB entry.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/kvm/book3s_hv_p9_entry.c | 22 ++++++++++++++++++----
 1 file changed, 18 insertions(+), 4 deletions(-)

diff --git a/arch/powerpc/kvm/book3s_hv_p9_entry.c b/arch/powerpc/kvm/book3s_hv_p9_entry.c
index d123813296ba..8fa48ba01f79 100644
--- a/arch/powerpc/kvm/book3s_hv_p9_entry.c
+++ b/arch/powerpc/kvm/book3s_hv_p9_entry.c
@@ -487,10 +487,22 @@ static void __accumulate_time(struct kvm_vcpu *vcpu, struct kvmhv_tb_accumulator
 #define accumulate_time(vcpu, next) do {} while (0)
 #endif
 
-static inline void mfslb(unsigned int idx, u64 *slbee, u64 *slbev)
+static inline u64 mfslbv(unsigned int idx)
 {
-	asm volatile("slbmfev  %0,%1" : "=r" (*slbev) : "r" (idx));
-	asm volatile("slbmfee  %0,%1" : "=r" (*slbee) : "r" (idx));
+	u64 slbev;
+
+	asm volatile("slbmfev  %0,%1" : "=r" (slbev) : "r" (idx));
+
+	return slbev;
+}
+
+static inline u64 mfslbe(unsigned int idx)
+{
+	u64 slbee;
+
+	asm volatile("slbmfee  %0,%1" : "=r" (slbee) : "r" (idx));
+
+	return slbee;
 }
 
 static inline void mtslb(u64 slbee, u64 slbev)
@@ -620,8 +632,10 @@ static void save_clear_guest_mmu(struct kvm *kvm, struct kvm_vcpu *vcpu)
 		 */
 		for (i = 0; i < vcpu->arch.slb_nr; i++) {
 			u64 slbee, slbev;
-			mfslb(i, &slbee, &slbev);
+
+			slbee = mfslbe(i);
 			if (slbee & SLB_ESID_V) {
+				slbev = mfslbv(i);
 				vcpu->arch.slb[nr].orige = slbee | i;
 				vcpu->arch.slb[nr].origv = slbev;
 				nr++;
-- 
2.23.0

[PATCH v4 47/53] KVM: PPC: Book3S HV P9: Avoid changing MSR[RI] in entry and exit

[Nicholas Piggin]

kvm_hstate.in_guest provides the equivalent of MSR[RI]=0 protection,
and it covers the existing MSR[RI]=0 section in late entry and early
exit, so clearing and setting MSR[RI] in those cases does not
actually do anything useful.

Remove the RI manipulation and replace it with comments. Make the
in_guest memory accesses a bit closer to a proper critical section
pattern. This speeds up guest entry/exit performance.

This also removes the MSR[RI] warnings which aren't very interesting
and would cause crashes if they hit due to causing an interrupt in
non-recoverable code.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/kvm/book3s_hv_p9_entry.c | 50 ++++++++++++---------------
 1 file changed, 23 insertions(+), 27 deletions(-)

diff --git a/arch/powerpc/kvm/book3s_hv_p9_entry.c b/arch/powerpc/kvm/book3s_hv_p9_entry.c
index 8fa48ba01f79..6120cdf281b9 100644
--- a/arch/powerpc/kvm/book3s_hv_p9_entry.c
+++ b/arch/powerpc/kvm/book3s_hv_p9_entry.c
@@ -904,7 +904,15 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
 	 * But TM could be split out if this would be a significant benefit.
 	 */
 
-	local_paca->kvm_hstate.in_guest = KVM_GUEST_MODE_HV_P9;
+	/*
+	 * MSR[RI] does not need to be cleared (and is not, for radix guests
+	 * with no prefetch bug), because in_guest is set. If we take a SRESET
+	 * or MCE with in_guest set but still in HV mode, then
+	 * kvmppc_p9_bad_interrupt handles the interrupt, which effectively
+	 * clears MSR[RI] and doesn't return.
+	 */
+	WRITE_ONCE(local_paca->kvm_hstate.in_guest, KVM_GUEST_MODE_HV_P9);
+	barrier(); /* Open in_guest critical section */
 
 	/*
 	 * Hash host, hash guest, or radix guest with prefetch bug, all have
@@ -916,14 +924,10 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
 
 	save_clear_host_mmu(kvm);
 
-	if (kvm_is_radix(kvm)) {
+	if (kvm_is_radix(kvm))
 		switch_mmu_to_guest_radix(kvm, vcpu, lpcr);
-		if (!cpu_has_feature(CPU_FTR_P9_RADIX_PREFETCH_BUG))
-			__mtmsrd(0, 1); /* clear RI */
-
-	} else {
+	else
 		switch_mmu_to_guest_hpt(kvm, vcpu, lpcr);
-	}
 
 	/* TLBIEL uses LPID=LPIDR, so run this after setting guest LPID */
 	check_need_tlb_flush(kvm, vc->pcpu, nested);
@@ -978,19 +982,16 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
 	vcpu->arch.regs.gpr[3] = local_paca->kvm_hstate.scratch2;
 
 	/*
-	 * Only set RI after reading machine check regs (DAR, DSISR, SRR0/1)
-	 * and hstate scratch (which we need to move into exsave to make
-	 * re-entrant vs SRESET/MCE)
+	 * After reading machine check regs (DAR, DSISR, SRR0/1) and hstate
+	 * scratch (which we need to move into exsave to make re-entrant vs
+	 * SRESET/MCE), register state is protected from reentrancy. However
+	 * timebase, MMU, among other state is still set to guest, so don't
+	 * enable MSR[RI] here. It gets enabled at the end, after in_guest
+	 * is cleared.
+	 *
+	 * It is possible an NMI could come in here, which is why it is
+	 * important to save the above state early so it can be debugged.
 	 */
-	if (ri_set) {
-		if (unlikely(!(mfmsr() & MSR_RI))) {
-			__mtmsrd(MSR_RI, 1);
-			WARN_ON_ONCE(1);
-		}
-	} else {
-		WARN_ON_ONCE(mfmsr() & MSR_RI);
-		__mtmsrd(MSR_RI, 1);
-	}
 
 	vcpu->arch.regs.gpr[9] = exsave[EX_R9/sizeof(u64)];
 	vcpu->arch.regs.gpr[10] = exsave[EX_R10/sizeof(u64)];
@@ -1048,13 +1049,6 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
 				 */
 				mtspr(SPRN_HSRR0, vcpu->arch.regs.nip);
 				mtspr(SPRN_HSRR1, vcpu->arch.shregs.msr);
-
-				/*
-				 * tm_return_to_guest re-loads SRR0/1, DAR,
-				 * DSISR after RI is cleared, in case they had
-				 * been clobbered by a MCE.
-				 */
-				__mtmsrd(0, 1); /* clear RI */
 				goto tm_return_to_guest;
 			}
 		}
@@ -1154,7 +1148,9 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
 
 	restore_p9_host_os_sprs(vcpu, &host_os_sprs);
 
-	local_paca->kvm_hstate.in_guest = KVM_GUEST_MODE_NONE;
+	barrier(); /* Close in_guest critical section */
+	WRITE_ONCE(local_paca->kvm_hstate.in_guest, KVM_GUEST_MODE_NONE);
+	/* Interrupts are recoverable at this point */
 
 	/*
 	 * cp_abort is required if the processor supports local copy-paste
-- 
2.23.0

[PATCH v4 48/53] KVM: PPC: Book3S HV P9: Add unlikely annotation for !mmu_ready

[Nicholas Piggin]

The mmu will almost always be ready.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/kvm/book3s_hv.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index e532a7010dba..4056605d3367 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -4426,7 +4426,7 @@ int kvmhv_run_single_vcpu(struct kvm_vcpu *vcpu, u64 time_limit,
 	vc->runner = vcpu;
 
 	/* See if the MMU is ready to go */
-	if (!kvm->arch.mmu_ready) {
+	if (unlikely(!kvm->arch.mmu_ready)) {
 		r = kvmhv_setup_mmu(vcpu);
 		if (r) {
 			run->exit_reason = KVM_EXIT_FAIL_ENTRY;
-- 
2.23.0

[PATCH v4 49/53] KVM: PPC: Book3S HV P9: Avoid cpu_in_guest atomics on entry and exit

[Nicholas Piggin]

cpu_in_guest is set to determine if a CPU needs to be IPI'ed to exit
the guest and notice the need_tlb_flush bit.

This can be implemented as a global per-CPU pointer to the currently
running guest instead of per-guest cpumasks, saving 2 atomics per
entry/exit. P7/8 doesn't require cpu_in_guest, nor does a nested HV
(only the L0 does), so move it to the P9 HV path.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/include/asm/kvm_book3s_64.h |  1 -
 arch/powerpc/include/asm/kvm_host.h      |  1 -
 arch/powerpc/kvm/book3s_hv.c             | 39 +++++++++++++-----------
 3 files changed, 22 insertions(+), 19 deletions(-)

diff --git a/arch/powerpc/include/asm/kvm_book3s_64.h b/arch/powerpc/include/asm/kvm_book3s_64.h
index 96f0fda50a07..fe07558173ef 100644
--- a/arch/powerpc/include/asm/kvm_book3s_64.h
+++ b/arch/powerpc/include/asm/kvm_book3s_64.h
@@ -44,7 +44,6 @@ struct kvm_nested_guest {
 	struct mutex tlb_lock;		/* serialize page faults and tlbies */
 	struct kvm_nested_guest *next;
 	cpumask_t need_tlb_flush;
-	cpumask_t cpu_in_guest;
 	short prev_cpu[NR_CPUS];
 	u8 radix;			/* is this nested guest radix */
 };
diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h
index d7004412b859..17263276189e 100644
--- a/arch/powerpc/include/asm/kvm_host.h
+++ b/arch/powerpc/include/asm/kvm_host.h
@@ -287,7 +287,6 @@ struct kvm_arch {
 	u32 online_vcores;
 	atomic_t hpte_mod_interest;
 	cpumask_t need_tlb_flush;
-	cpumask_t cpu_in_guest;
 	u8 radix;
 	u8 fwnmi_enabled;
 	u8 secure_guest;
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 4056605d3367..00c1e102c103 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -3009,19 +3009,18 @@ static void kvmppc_release_hwthread(int cpu)
 	tpaca->kvm_hstate.kvm_split_mode = NULL;
 }
 
+static DEFINE_PER_CPU(struct kvm *, cpu_in_guest);
+
 static void radix_flush_cpu(struct kvm *kvm, int cpu, struct kvm_vcpu *vcpu)
 {
 	struct kvm_nested_guest *nested = vcpu->arch.nested;
-	cpumask_t *cpu_in_guest, *need_tlb_flush;
+	cpumask_t *need_tlb_flush;
 	int i;
 
-	if (nested) {
+	if (nested)
 		need_tlb_flush = &nested->need_tlb_flush;
-		cpu_in_guest = &nested->cpu_in_guest;
-	} else {
+	else
 		need_tlb_flush = &kvm->arch.need_tlb_flush;
-		cpu_in_guest = &kvm->arch.cpu_in_guest;
-	}
 
 	cpu = cpu_first_tlb_thread_sibling(cpu);
 	for (i = cpu; i <= cpu_last_tlb_thread_sibling(cpu);
@@ -3029,16 +3028,21 @@ static void radix_flush_cpu(struct kvm *kvm, int cpu, struct kvm_vcpu *vcpu)
 		cpumask_set_cpu(i, need_tlb_flush);
 
 	/*
-	 * Make sure setting of bit in need_tlb_flush precedes
-	 * testing of cpu_in_guest bits.  The matching barrier on
-	 * the other side is the first smp_mb() in kvmppc_run_core().
+	 * Make sure setting of bit in need_tlb_flush precedes testing of
+	 * cpu_in_guest. The matching barrier on the other side is hwsync
+	 * when switching to guest MMU mode, which happens between
+	 * cpu_in_guest being set to the guest kvm, and need_tlb_flush bit
+	 * being tested.
 	 */
 	smp_mb();
 
 	for (i = cpu; i <= cpu_last_tlb_thread_sibling(cpu);
-					i += cpu_tlb_thread_sibling_step())
-		if (cpumask_test_cpu(i, cpu_in_guest))
+					i += cpu_tlb_thread_sibling_step()) {
+		struct kvm *running = *per_cpu_ptr(&cpu_in_guest, i);
+
+		if (running == kvm)
 			smp_call_function_single(i, do_nothing, NULL, 1);
+	}
 }
 
 static void do_migrate_away_vcpu(void *arg)
@@ -3105,7 +3109,6 @@ static void kvmppc_start_thread(struct kvm_vcpu *vcpu, struct kvmppc_vcore *vc)
 {
 	int cpu;
 	struct paca_struct *tpaca;
-	struct kvm *kvm = vc->kvm;
 
 	cpu = vc->pcpu;
 	if (vcpu) {
@@ -3116,7 +3119,6 @@ static void kvmppc_start_thread(struct kvm_vcpu *vcpu, struct kvmppc_vcore *vc)
 		cpu += vcpu->arch.ptid;
 		vcpu->cpu = vc->pcpu;
 		vcpu->arch.thread_cpu = cpu;
-		cpumask_set_cpu(cpu, &kvm->arch.cpu_in_guest);
 	}
 	tpaca = paca_ptrs[cpu];
 	tpaca->kvm_hstate.kvm_vcpu = vcpu;
@@ -3847,7 +3849,6 @@ static noinline void kvmppc_run_core(struct kvmppc_vcore *vc)
 		kvmppc_release_hwthread(pcpu + i);
 		if (sip && sip->napped[i])
 			kvmppc_ipi_thread(pcpu + i);
-		cpumask_clear_cpu(pcpu + i, &vc->kvm->arch.cpu_in_guest);
 	}
 
 	spin_unlock(&vc->lock);
@@ -4015,8 +4016,14 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
 		}
 
 	} else {
+		struct kvm *kvm = vcpu->kvm;
+
 		kvmppc_xive_push_vcpu(vcpu);
+
+		__this_cpu_write(cpu_in_guest, kvm);
 		trap = kvmhv_vcpu_entry_p9(vcpu, time_limit, lpcr, tb);
+		__this_cpu_write(cpu_in_guest, NULL);
+
 		if (trap == BOOK3S_INTERRUPT_SYSCALL && !vcpu->arch.nested &&
 		    !(vcpu->arch.shregs.msr & MSR_PR)) {
 			unsigned long req = kvmppc_get_gpr(vcpu, 3);
@@ -4041,7 +4048,7 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
 		}
 		kvmppc_xive_pull_vcpu(vcpu);
 
-		if (kvm_is_radix(vcpu->kvm))
+		if (kvm_is_radix(kvm))
 			vcpu->arch.slb_max = 0;
 	}
 
@@ -4531,8 +4538,6 @@ int kvmhv_run_single_vcpu(struct kvm_vcpu *vcpu, u64 time_limit,
 
 	powerpc_local_irq_pmu_restore(flags);
 
-	cpumask_clear_cpu(pcpu, &kvm->arch.cpu_in_guest);
-
 	preempt_enable();
 
 	/*
-- 
2.23.0

[PATCH v4 50/53] KVM: PPC: Book3S HV P9: Remove most of the vcore logic

[Nicholas Piggin]

The P9 path always uses one vcpu per vcore, so none of the vcore, locks,
stolen time, blocking logic, shared waitq, etc., is required.

Remove most of it.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/kvm/book3s_hv.c | 147 ++++++++++++++++++++---------------
 1 file changed, 85 insertions(+), 62 deletions(-)

diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 00c1e102c103..e56804b84804 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -276,6 +276,8 @@ static void kvmppc_core_start_stolen(struct kvmppc_vcore *vc, u64 tb)
 {
 	unsigned long flags;
 
+	WARN_ON_ONCE(cpu_has_feature(CPU_FTR_ARCH_300));
+
 	spin_lock_irqsave(&vc->stoltb_lock, flags);
 	vc->preempt_tb = tb;
 	spin_unlock_irqrestore(&vc->stoltb_lock, flags);
@@ -285,6 +287,8 @@ static void kvmppc_core_end_stolen(struct kvmppc_vcore *vc, u64 tb)
 {
 	unsigned long flags;
 
+	WARN_ON_ONCE(cpu_has_feature(CPU_FTR_ARCH_300));
+
 	spin_lock_irqsave(&vc->stoltb_lock, flags);
 	if (vc->preempt_tb != TB_NIL) {
 		vc->stolen_tb += tb - vc->preempt_tb;
@@ -297,7 +301,12 @@ static void kvmppc_core_vcpu_load_hv(struct kvm_vcpu *vcpu, int cpu)
 {
 	struct kvmppc_vcore *vc = vcpu->arch.vcore;
 	unsigned long flags;
-	u64 now = mftb();
+	u64 now;
+
+	if (cpu_has_feature(CPU_FTR_ARCH_300))
+		return;
+
+	now = mftb();
 
 	/*
 	 * We can test vc->runner without taking the vcore lock,
@@ -321,7 +330,12 @@ static void kvmppc_core_vcpu_put_hv(struct kvm_vcpu *vcpu)
 {
 	struct kvmppc_vcore *vc = vcpu->arch.vcore;
 	unsigned long flags;
-	u64 now = mftb();
+	u64 now;
+
+	if (cpu_has_feature(CPU_FTR_ARCH_300))
+		return;
+
+	now = mftb();
 
 	if (vc->runner == vcpu && vc->vcore_state >= VCORE_SLEEPING)
 		kvmppc_core_start_stolen(vc, now);
@@ -673,6 +687,8 @@ static u64 vcore_stolen_time(struct kvmppc_vcore *vc, u64 now)
 	u64 p;
 	unsigned long flags;
 
+	WARN_ON_ONCE(cpu_has_feature(CPU_FTR_ARCH_300));
+
 	spin_lock_irqsave(&vc->stoltb_lock, flags);
 	p = vc->stolen_tb;
 	if (vc->vcore_state != VCORE_INACTIVE &&
@@ -695,13 +711,19 @@ static void kvmppc_create_dtl_entry(struct kvm_vcpu *vcpu,
 	dt = vcpu->arch.dtl_ptr;
 	vpa = vcpu->arch.vpa.pinned_addr;
 	now = tb;
-	core_stolen = vcore_stolen_time(vc, now);
-	stolen = core_stolen - vcpu->arch.stolen_logged;
-	vcpu->arch.stolen_logged = core_stolen;
-	spin_lock_irqsave(&vcpu->arch.tbacct_lock, flags);
-	stolen += vcpu->arch.busy_stolen;
-	vcpu->arch.busy_stolen = 0;
-	spin_unlock_irqrestore(&vcpu->arch.tbacct_lock, flags);
+
+	if (cpu_has_feature(CPU_FTR_ARCH_300)) {
+		stolen = 0;
+	} else {
+		core_stolen = vcore_stolen_time(vc, now);
+		stolen = core_stolen - vcpu->arch.stolen_logged;
+		vcpu->arch.stolen_logged = core_stolen;
+		spin_lock_irqsave(&vcpu->arch.tbacct_lock, flags);
+		stolen += vcpu->arch.busy_stolen;
+		vcpu->arch.busy_stolen = 0;
+		spin_unlock_irqrestore(&vcpu->arch.tbacct_lock, flags);
+	}
+
 	if (!dt || !vpa)
 		return;
 	memset(dt, 0, sizeof(struct dtl_entry));
@@ -898,13 +920,14 @@ static int kvm_arch_vcpu_yield_to(struct kvm_vcpu *target)
 	 * mode handler is not called but no other threads are in the
 	 * source vcore.
 	 */
-
-	spin_lock(&vcore->lock);
-	if (target->arch.state == KVMPPC_VCPU_RUNNABLE &&
-	    vcore->vcore_state != VCORE_INACTIVE &&
-	    vcore->runner)
-		target = vcore->runner;
-	spin_unlock(&vcore->lock);
+	if (!cpu_has_feature(CPU_FTR_ARCH_300)) {
+		spin_lock(&vcore->lock);
+		if (target->arch.state == KVMPPC_VCPU_RUNNABLE &&
+		    vcore->vcore_state != VCORE_INACTIVE &&
+		    vcore->runner)
+			target = vcore->runner;
+		spin_unlock(&vcore->lock);
+	}
 
 	return kvm_vcpu_yield_to(target);
 }
@@ -3131,13 +3154,6 @@ static void kvmppc_start_thread(struct kvm_vcpu *vcpu, struct kvmppc_vcore *vc)
 		kvmppc_ipi_thread(cpu);
 }
 
-/* Old path does this in asm */
-static void kvmppc_stop_thread(struct kvm_vcpu *vcpu)
-{
-	vcpu->cpu = -1;
-	vcpu->arch.thread_cpu = -1;
-}
-
 static void kvmppc_wait_for_nap(int n_threads)
 {
 	int cpu = smp_processor_id();
@@ -3226,6 +3242,8 @@ static void kvmppc_vcore_preempt(struct kvmppc_vcore *vc)
 {
 	struct preempted_vcore_list *lp = this_cpu_ptr(&preempted_vcores);
 
+	WARN_ON_ONCE(cpu_has_feature(CPU_FTR_ARCH_300));
+
 	vc->vcore_state = VCORE_PREEMPT;
 	vc->pcpu = smp_processor_id();
 	if (vc->num_threads < threads_per_vcore(vc->kvm)) {
@@ -3242,6 +3260,8 @@ static void kvmppc_vcore_end_preempt(struct kvmppc_vcore *vc)
 {
 	struct preempted_vcore_list *lp;
 
+	WARN_ON_ONCE(cpu_has_feature(CPU_FTR_ARCH_300));
+
 	kvmppc_core_end_stolen(vc, mftb());
 	if (!list_empty(&vc->preempt_list)) {
 		lp = &per_cpu(preempted_vcores, vc->pcpu);
@@ -3983,7 +4003,6 @@ static int kvmhv_vcpu_entry_p9_nested(struct kvm_vcpu *vcpu, u64 time_limit, uns
 static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
 			 unsigned long lpcr, u64 *tb)
 {
-	struct kvmppc_vcore *vc = vcpu->arch.vcore;
 	u64 next_timer;
 	int trap;
 
@@ -3999,9 +4018,6 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
 
 	kvmppc_subcore_enter_guest();
 
-	vc->entry_exit_map = 1;
-	vc->in_guest = 1;
-
 	vcpu_vpa_increment_dispatch(vcpu);
 
 	if (kvmhv_on_pseries()) {
@@ -4054,9 +4070,6 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
 
 	vcpu_vpa_increment_dispatch(vcpu);
 
-	vc->entry_exit_map = 0x101;
-	vc->in_guest = 0;
-
 	kvmppc_subcore_exit_guest();
 
 	return trap;
@@ -4122,6 +4135,13 @@ static bool kvmppc_vcpu_woken(struct kvm_vcpu *vcpu)
 	return false;
 }
 
+static bool kvmppc_vcpu_check_block(struct kvm_vcpu *vcpu)
+{
+	if (!vcpu->arch.ceded || kvmppc_vcpu_woken(vcpu))
+		return true;
+	return false;
+}
+
 /*
  * Check to see if any of the runnable vcpus on the vcore have pending
  * exceptions or are no longer ceded
@@ -4132,7 +4152,7 @@ static int kvmppc_vcore_check_block(struct kvmppc_vcore *vc)
 	int i;
 
 	for_each_runnable_thread(i, vcpu, vc) {
-		if (!vcpu->arch.ceded || kvmppc_vcpu_woken(vcpu))
+		if (kvmppc_vcpu_check_block(vcpu))
 			return 1;
 	}
 
@@ -4149,6 +4169,8 @@ static void kvmppc_vcore_blocked(struct kvmppc_vcore *vc)
 	int do_sleep = 1;
 	u64 block_ns;
 
+	WARN_ON_ONCE(cpu_has_feature(CPU_FTR_ARCH_300));
+
 	/* Poll for pending exceptions and ceded state */
 	cur = start_poll = ktime_get();
 	if (vc->halt_poll_ns) {
@@ -4426,11 +4448,7 @@ int kvmhv_run_single_vcpu(struct kvm_vcpu *vcpu, u64 time_limit,
 	vcpu->arch.ceded = 0;
 	vcpu->arch.run_task = current;
 	vcpu->arch.state = KVMPPC_VCPU_RUNNABLE;
-	vcpu->arch.busy_preempt = TB_NIL;
 	vcpu->arch.last_inst = KVM_INST_FETCH_FAILED;
-	vc->runnable_threads[0] = vcpu;
-	vc->n_runnable = 1;
-	vc->runner = vcpu;
 
 	/* See if the MMU is ready to go */
 	if (unlikely(!kvm->arch.mmu_ready)) {
@@ -4448,11 +4466,8 @@ int kvmhv_run_single_vcpu(struct kvm_vcpu *vcpu, u64 time_limit,
 
 	kvmppc_update_vpas(vcpu);
 
-	init_vcore_to_run(vc);
-
 	preempt_disable();
 	pcpu = smp_processor_id();
-	vc->pcpu = pcpu;
 	if (kvm_is_radix(kvm))
 		kvmppc_prepare_radix_vcpu(vcpu, pcpu);
 
@@ -4481,21 +4496,23 @@ int kvmhv_run_single_vcpu(struct kvm_vcpu *vcpu, u64 time_limit,
 		goto out;
 	}
 
-	tb = mftb();
+	if (vcpu->arch.timer_running) {
+		hrtimer_try_to_cancel(&vcpu->arch.dec_timer);
+		vcpu->arch.timer_running = 0;
+	}
 
-	vcpu->arch.stolen_logged = vcore_stolen_time(vc, tb);
-	vc->preempt_tb = TB_NIL;
+	tb = mftb();
 
-	kvmppc_clear_host_core(pcpu);
+	vcpu->cpu = pcpu;
+	vcpu->arch.thread_cpu = pcpu;
+	vc->pcpu = pcpu;
+	local_paca->kvm_hstate.kvm_vcpu = vcpu;
+	local_paca->kvm_hstate.ptid = 0;
+	local_paca->kvm_hstate.fake_suspend = 0;
 
-	local_paca->kvm_hstate.napping = 0;
-	local_paca->kvm_hstate.kvm_split_mode = NULL;
-	kvmppc_start_thread(vcpu, vc);
 	kvmppc_create_dtl_entry(vcpu, vc, tb);
-	trace_kvm_guest_enter(vcpu);
 
-	vc->vcore_state = VCORE_RUNNING;
-	trace_kvmppc_run_core(vc, 0);
+	trace_kvm_guest_enter(vcpu);
 
 	guest_enter_irqoff();
 
@@ -4517,8 +4534,6 @@ int kvmhv_run_single_vcpu(struct kvm_vcpu *vcpu, u64 time_limit,
 
 	set_irq_happened(trap);
 
-	kvmppc_set_host_core(pcpu);
-
 	context_tracking_guest_exit();
 	if (!vtime_accounting_enabled_this_cpu()) {
 		local_irq_enable();
@@ -4534,7 +4549,8 @@ int kvmhv_run_single_vcpu(struct kvm_vcpu *vcpu, u64 time_limit,
 	}
 	vtime_account_guest_exit();
 
-	kvmppc_stop_thread(vcpu);
+	vcpu->cpu = -1;
+	vcpu->arch.thread_cpu = -1;
 
 	powerpc_local_irq_pmu_restore(flags);
 
@@ -4561,28 +4577,31 @@ int kvmhv_run_single_vcpu(struct kvm_vcpu *vcpu, u64 time_limit,
 	}
 	vcpu->arch.ret = r;
 
-	if (is_kvmppc_resume_guest(r) && vcpu->arch.ceded &&
-	    !kvmppc_vcpu_woken(vcpu)) {
+	if (is_kvmppc_resume_guest(r) && !kvmppc_vcpu_check_block(vcpu)) {
 		kvmppc_set_timer(vcpu);
-		while (vcpu->arch.ceded && !kvmppc_vcpu_woken(vcpu)) {
+
+		prepare_to_rcuwait(&vcpu->wait);
+		for (;;) {
+			set_current_state(TASK_INTERRUPTIBLE);
 			if (signal_pending(current)) {
 				vcpu->stat.signal_exits++;
 				run->exit_reason = KVM_EXIT_INTR;
 				vcpu->arch.ret = -EINTR;
 				break;
 			}
-			spin_lock(&vc->lock);
-			kvmppc_vcore_blocked(vc);
-			spin_unlock(&vc->lock);
+
+			if (kvmppc_vcpu_check_block(vcpu))
+				break;
+
+			trace_kvmppc_vcore_blocked(vc, 0);
+			schedule();
+			trace_kvmppc_vcore_blocked(vc, 1);
 		}
+		finish_rcuwait(&vcpu->wait);
 	}
 	vcpu->arch.ceded = 0;
 
-	vc->vcore_state = VCORE_INACTIVE;
-	trace_kvmppc_run_core(vc, 1);
-
  done:
-	kvmppc_remove_runnable(vc, vcpu, tb);
 	trace_kvmppc_run_vcpu_exit(vcpu);
 
 	return vcpu->arch.ret;
@@ -4664,7 +4683,8 @@ static int kvmppc_vcpu_run_hv(struct kvm_vcpu *vcpu)
 
 	kvmppc_save_current_sprs();
 
-	vcpu->arch.waitp = &vcpu->arch.vcore->wait;
+	if (!cpu_has_feature(CPU_FTR_ARCH_300))
+		vcpu->arch.waitp = &vcpu->arch.vcore->wait;
 	vcpu->arch.pgdir = kvm->mm->pgd;
 	vcpu->arch.state = KVMPPC_VCPU_BUSY_IN_HOST;
 
@@ -5126,6 +5146,9 @@ void kvmppc_alloc_host_rm_ops(void)
 	int cpu, core;
 	int size;
 
+	if (cpu_has_feature(CPU_FTR_ARCH_300))
+		return;
+
 	/* Not the first time here ? */
 	if (kvmppc_host_rm_ops_hv != NULL)
 		return;
-- 
2.23.0

[PATCH v4 51/53] KVM: PPC: Book3S HV P9: Tidy kvmppc_create_dtl_entry

[Nicholas Piggin]

This goes further to removing vcores from the P9 path. Also avoid the
memset in favour of explicitly initialising all fields.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/kvm/book3s_hv.c | 60 +++++++++++++++++++++---------------
 1 file changed, 35 insertions(+), 25 deletions(-)

diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index e56804b84804..2d598291d8cf 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -698,41 +698,30 @@ static u64 vcore_stolen_time(struct kvmppc_vcore *vc, u64 now)
 	return p;
 }
 
-static void kvmppc_create_dtl_entry(struct kvm_vcpu *vcpu,
-				    struct kvmppc_vcore *vc, u64 tb)
+static void __kvmppc_create_dtl_entry(struct kvm_vcpu *vcpu,
+					unsigned int pcpu, u64 now,
+					unsigned long stolen)
 {
 	struct dtl_entry *dt;
 	struct lppaca *vpa;
-	unsigned long stolen;
-	unsigned long core_stolen;
-	u64 now;
-	unsigned long flags;
 
 	dt = vcpu->arch.dtl_ptr;
 	vpa = vcpu->arch.vpa.pinned_addr;
-	now = tb;
-
-	if (cpu_has_feature(CPU_FTR_ARCH_300)) {
-		stolen = 0;
-	} else {
-		core_stolen = vcore_stolen_time(vc, now);
-		stolen = core_stolen - vcpu->arch.stolen_logged;
-		vcpu->arch.stolen_logged = core_stolen;
-		spin_lock_irqsave(&vcpu->arch.tbacct_lock, flags);
-		stolen += vcpu->arch.busy_stolen;
-		vcpu->arch.busy_stolen = 0;
-		spin_unlock_irqrestore(&vcpu->arch.tbacct_lock, flags);
-	}
 
 	if (!dt || !vpa)
 		return;
-	memset(dt, 0, sizeof(struct dtl_entry));
+
 	dt->dispatch_reason = 7;
-	dt->processor_id = cpu_to_be16(vc->pcpu + vcpu->arch.ptid);
-	dt->timebase = cpu_to_be64(now + vc->tb_offset);
+	dt->preempt_reason = 0;
+	dt->processor_id = cpu_to_be16(pcpu + vcpu->arch.ptid);
 	dt->enqueue_to_dispatch_time = cpu_to_be32(stolen);
+	dt->ready_to_enqueue_time = 0;
+	dt->waiting_to_ready_time = 0;
+	dt->timebase = cpu_to_be64(now);
+	dt->fault_addr = 0;
 	dt->srr0 = cpu_to_be64(kvmppc_get_pc(vcpu));
 	dt->srr1 = cpu_to_be64(vcpu->arch.shregs.msr);
+
 	++dt;
 	if (dt == vcpu->arch.dtl.pinned_end)
 		dt = vcpu->arch.dtl.pinned_addr;
@@ -743,6 +732,27 @@ static void kvmppc_create_dtl_entry(struct kvm_vcpu *vcpu,
 	vcpu->arch.dtl.dirty = true;
 }
 
+static void kvmppc_create_dtl_entry(struct kvm_vcpu *vcpu,
+				    struct kvmppc_vcore *vc)
+{
+	unsigned long stolen;
+	unsigned long core_stolen;
+	u64 now;
+	unsigned long flags;
+
+	now = mftb();
+
+	core_stolen = vcore_stolen_time(vc, now);
+	stolen = core_stolen - vcpu->arch.stolen_logged;
+	vcpu->arch.stolen_logged = core_stolen;
+	spin_lock_irqsave(&vcpu->arch.tbacct_lock, flags);
+	stolen += vcpu->arch.busy_stolen;
+	vcpu->arch.busy_stolen = 0;
+	spin_unlock_irqrestore(&vcpu->arch.tbacct_lock, flags);
+
+	__kvmppc_create_dtl_entry(vcpu, vc->pcpu, now + vc->tb_offset, stolen);
+}
+
 /* See if there is a doorbell interrupt pending for a vcpu */
 static bool kvmppc_doorbell_pending(struct kvm_vcpu *vcpu)
 {
@@ -3756,7 +3766,7 @@ static noinline void kvmppc_run_core(struct kvmppc_vcore *vc)
 		pvc->pcpu = pcpu + thr;
 		for_each_runnable_thread(i, vcpu, pvc) {
 			kvmppc_start_thread(vcpu, pvc);
-			kvmppc_create_dtl_entry(vcpu, pvc, mftb());
+			kvmppc_create_dtl_entry(vcpu, pvc);
 			trace_kvm_guest_enter(vcpu);
 			if (!vcpu->arch.ptid)
 				thr0_done = true;
@@ -4332,7 +4342,7 @@ static int kvmppc_run_vcpu(struct kvm_vcpu *vcpu)
 		if ((vc->vcore_state == VCORE_PIGGYBACK ||
 		     vc->vcore_state == VCORE_RUNNING) &&
 			   !VCORE_IS_EXITING(vc)) {
-			kvmppc_create_dtl_entry(vcpu, vc, mftb());
+			kvmppc_create_dtl_entry(vcpu, vc);
 			kvmppc_start_thread(vcpu, vc);
 			trace_kvm_guest_enter(vcpu);
 		} else if (vc->vcore_state == VCORE_SLEEPING) {
@@ -4510,7 +4520,7 @@ int kvmhv_run_single_vcpu(struct kvm_vcpu *vcpu, u64 time_limit,
 	local_paca->kvm_hstate.ptid = 0;
 	local_paca->kvm_hstate.fake_suspend = 0;
 
-	kvmppc_create_dtl_entry(vcpu, vc, tb);
+	__kvmppc_create_dtl_entry(vcpu, pcpu, tb + vc->tb_offset, 0);
 
 	trace_kvm_guest_enter(vcpu);
 
-- 
2.23.0

[PATCH v4 52/53] KVM: PPC: Book3S HV P9: Stop using vc->dpdes

[Nicholas Piggin]

The P9 path uses vc->dpdes only for msgsndp / SMT emulation. This adds
an ordering requirement between vcpu->doorbell_request and vc->dpdes for
no real benefit. Use vcpu->doorbell_request directly.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/kvm/book3s_hv.c          | 18 ++++++++++--------
 arch/powerpc/kvm/book3s_hv_builtin.c  |  2 ++
 arch/powerpc/kvm/book3s_hv_p9_entry.c | 14 ++++++++++----
 3 files changed, 22 insertions(+), 12 deletions(-)

diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 2d598291d8cf..214481e5d56d 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -761,6 +761,8 @@ static bool kvmppc_doorbell_pending(struct kvm_vcpu *vcpu)
 
 	if (vcpu->arch.doorbell_request)
 		return true;
+	if (cpu_has_feature(CPU_FTR_ARCH_300))
+		return false;
 	/*
 	 * Ensure that the read of vcore->dpdes comes after the read
 	 * of vcpu->doorbell_request.  This barrier matches the
@@ -2185,8 +2187,10 @@ static int kvmppc_get_one_reg_hv(struct kvm_vcpu *vcpu, u64 id,
 		 * either vcore->dpdes or doorbell_request.
 		 * On POWER8, doorbell_request is 0.
 		 */
-		*val = get_reg_val(id, vcpu->arch.vcore->dpdes |
-				   vcpu->arch.doorbell_request);
+		if (cpu_has_feature(CPU_FTR_ARCH_300))
+			*val = get_reg_val(id, vcpu->arch.doorbell_request);
+		else
+			*val = get_reg_val(id, vcpu->arch.vcore->dpdes);
 		break;
 	case KVM_REG_PPC_VTB:
 		*val = get_reg_val(id, vcpu->arch.vcore->vtb);
@@ -2423,7 +2427,10 @@ static int kvmppc_set_one_reg_hv(struct kvm_vcpu *vcpu, u64 id,
 		vcpu->arch.pspb = set_reg_val(id, *val);
 		break;
 	case KVM_REG_PPC_DPDES:
-		vcpu->arch.vcore->dpdes = set_reg_val(id, *val);
+		if (cpu_has_feature(CPU_FTR_ARCH_300))
+			vcpu->arch.doorbell_request = set_reg_val(id, *val) & 1;
+		else
+			vcpu->arch.vcore->dpdes = set_reg_val(id, *val);
 		break;
 	case KVM_REG_PPC_VTB:
 		vcpu->arch.vcore->vtb = set_reg_val(id, *val);
@@ -4491,11 +4498,6 @@ int kvmhv_run_single_vcpu(struct kvm_vcpu *vcpu, u64 time_limit,
 
 	if (!nested) {
 		kvmppc_core_prepare_to_enter(vcpu);
-		if (vcpu->arch.doorbell_request) {
-			vc->dpdes = 1;
-			smp_wmb();
-			vcpu->arch.doorbell_request = 0;
-		}
 		if (test_bit(BOOK3S_IRQPRIO_EXTERNAL,
 			     &vcpu->arch.pending_exceptions))
 			lpcr |= LPCR_MER;
diff --git a/arch/powerpc/kvm/book3s_hv_builtin.c b/arch/powerpc/kvm/book3s_hv_builtin.c
index ad70756a777c..7d6d91338c3f 100644
--- a/arch/powerpc/kvm/book3s_hv_builtin.c
+++ b/arch/powerpc/kvm/book3s_hv_builtin.c
@@ -649,6 +649,8 @@ void kvmppc_guest_entry_inject_int(struct kvm_vcpu *vcpu)
 	int ext;
 	unsigned long lpcr;
 
+	WARN_ON_ONCE(cpu_has_feature(CPU_FTR_ARCH_300));
+
 	/* Insert EXTERNAL bit into LPCR at the MER bit position */
 	ext = (vcpu->arch.pending_exceptions >> BOOK3S_IRQPRIO_EXTERNAL) & 1;
 	lpcr = mfspr(SPRN_LPCR);
diff --git a/arch/powerpc/kvm/book3s_hv_p9_entry.c b/arch/powerpc/kvm/book3s_hv_p9_entry.c
index 6120cdf281b9..72119bc13e1d 100644
--- a/arch/powerpc/kvm/book3s_hv_p9_entry.c
+++ b/arch/powerpc/kvm/book3s_hv_p9_entry.c
@@ -780,6 +780,7 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
 	unsigned long host_pidr;
 	unsigned long host_dawr1;
 	unsigned long host_dawrx1;
+	unsigned long dpdes;
 
 	hdec = time_limit - *tb;
 	if (hdec < 0)
@@ -842,8 +843,10 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
 
 	if (vc->pcr)
 		mtspr(SPRN_PCR, vc->pcr | PCR_MASK);
-	if (vc->dpdes)
-		mtspr(SPRN_DPDES, vc->dpdes);
+	if (vcpu->arch.doorbell_request) {
+		vcpu->arch.doorbell_request = 0;
+		mtspr(SPRN_DPDES, 1);
+	}
 
 	if (dawr_enabled()) {
 		if (vcpu->arch.dawr0 != host_dawr0)
@@ -1074,7 +1077,10 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
 	vcpu->arch.shregs.sprg2 = mfspr(SPRN_SPRG2);
 	vcpu->arch.shregs.sprg3 = mfspr(SPRN_SPRG3);
 
-	vc->dpdes = mfspr(SPRN_DPDES);
+	dpdes = mfspr(SPRN_DPDES);
+	if (dpdes)
+		vcpu->arch.doorbell_request = 1;
+
 	vc->vtb = mfspr(SPRN_VTB);
 
 	dec = mfspr(SPRN_DEC);
@@ -1136,7 +1142,7 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
 		}
 	}
 
-	if (vc->dpdes)
+	if (dpdes)
 		mtspr(SPRN_DPDES, 0);
 	if (vc->pcr)
 		mtspr(SPRN_PCR, PCR_MASK);
-- 
2.23.0

[PATCH v4 53/53] KVM: PPC: Book3S HV P9: Remove subcore HMI handling

[Nicholas Piggin]

On POWER9 and newer, rather than the complex HMI synchronisation and
subcore state, have each thread un-apply the guest TB offset before
calling into the early HMI handler.

This allows the subcore state to be avoided, including subcore enter
/ exit guest, which includes an expensive divide that shows up
slightly in profiles.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/include/asm/kvm_ppc.h    |  1 +
 arch/powerpc/kvm/book3s_hv.c          | 12 +++---
 arch/powerpc/kvm/book3s_hv_hmi.c      |  7 +++-
 arch/powerpc/kvm/book3s_hv_p9_entry.c |  2 +-
 arch/powerpc/kvm/book3s_hv_ras.c      | 54 +++++++++++++++++++++++++++
 5 files changed, 67 insertions(+), 9 deletions(-)

diff --git a/arch/powerpc/include/asm/kvm_ppc.h b/arch/powerpc/include/asm/kvm_ppc.h
index 2b76d51e4b13..33db83b82fbd 100644
--- a/arch/powerpc/include/asm/kvm_ppc.h
+++ b/arch/powerpc/include/asm/kvm_ppc.h
@@ -759,6 +759,7 @@ void kvmppc_realmode_machine_check(struct kvm_vcpu *vcpu);
 void kvmppc_subcore_enter_guest(void);
 void kvmppc_subcore_exit_guest(void);
 long kvmppc_realmode_hmi_handler(void);
+long kvmppc_p9_realmode_hmi_handler(struct kvm_vcpu *vcpu);
 long kvmppc_h_enter(struct kvm_vcpu *vcpu, unsigned long flags,
                     long pte_index, unsigned long pteh, unsigned long ptel);
 long kvmppc_h_remove(struct kvm_vcpu *vcpu, unsigned long flags,
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 214481e5d56d..98e90bdf1f27 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -4033,8 +4033,6 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
 
 	vcpu->arch.ceded = 0;
 
-	kvmppc_subcore_enter_guest();
-
 	vcpu_vpa_increment_dispatch(vcpu);
 
 	if (kvmhv_on_pseries()) {
@@ -4087,8 +4085,6 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
 
 	vcpu_vpa_increment_dispatch(vcpu);
 
-	kvmppc_subcore_exit_guest();
-
 	return trap;
 }
 
@@ -6102,9 +6098,11 @@ static int kvmppc_book3s_init_hv(void)
 	if (r)
 		return r;
 
-	r = kvm_init_subcore_bitmap();
-	if (r)
-		return r;
+	if (!cpu_has_feature(CPU_FTR_ARCH_300)) {
+		r = kvm_init_subcore_bitmap();
+		if (r)
+			return r;
+	}
 
 	/*
 	 * We need a way of accessing the XICS interrupt controller,
diff --git a/arch/powerpc/kvm/book3s_hv_hmi.c b/arch/powerpc/kvm/book3s_hv_hmi.c
index 9af660476314..1ec50c69678b 100644
--- a/arch/powerpc/kvm/book3s_hv_hmi.c
+++ b/arch/powerpc/kvm/book3s_hv_hmi.c
@@ -20,10 +20,15 @@ void wait_for_subcore_guest_exit(void)
 
 	/*
 	 * NULL bitmap pointer indicates that KVM module hasn't
-	 * been loaded yet and hence no guests are running.
+	 * been loaded yet and hence no guests are running, or running
+	 * on POWER9 or newer CPU.
+	 *
 	 * 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.
+	 *
+	 * POWER9 and newer don't need this synchronisation.
+	 *
 	 * Hence, just return from here.
 	 */
 	if (!local_paca->sibling_subcore_state)
diff --git a/arch/powerpc/kvm/book3s_hv_p9_entry.c b/arch/powerpc/kvm/book3s_hv_p9_entry.c
index 72119bc13e1d..ebb4781859e2 100644
--- a/arch/powerpc/kvm/book3s_hv_p9_entry.c
+++ b/arch/powerpc/kvm/book3s_hv_p9_entry.c
@@ -1013,7 +1013,7 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
 		kvmppc_realmode_machine_check(vcpu);
 
 	} else if (unlikely(trap == BOOK3S_INTERRUPT_HMI)) {
-		kvmppc_realmode_hmi_handler();
+		kvmppc_p9_realmode_hmi_handler(vcpu);
 
 	} else if (trap == BOOK3S_INTERRUPT_H_EMUL_ASSIST) {
 		vcpu->arch.emul_inst = mfspr(SPRN_HEIR);
diff --git a/arch/powerpc/kvm/book3s_hv_ras.c b/arch/powerpc/kvm/book3s_hv_ras.c
index d4bca93b79f6..ccfd96965630 100644
--- a/arch/powerpc/kvm/book3s_hv_ras.c
+++ b/arch/powerpc/kvm/book3s_hv_ras.c
@@ -136,6 +136,60 @@ void kvmppc_realmode_machine_check(struct kvm_vcpu *vcpu)
 	vcpu->arch.mce_evt = mce_evt;
 }
 
+
+long kvmppc_p9_realmode_hmi_handler(struct kvm_vcpu *vcpu)
+{
+	struct kvmppc_vcore *vc = vcpu->arch.vcore;
+	long ret = 0;
+
+	/*
+	 * Unapply and clear the offset first. That way, if the TB was not
+	 * resynced then it will remain in host-offset, and if it was resynced
+	 * then it is brought into host-offset. Then the tb offset is
+	 * re-applied before continuing with the KVM exit.
+	 *
+	 * This way, we don't need to actually know whether not OPAL resynced
+	 * the timebase or do any of the complicated dance that the P7/8
+	 * path requires.
+	 */
+	if (vc->tb_offset_applied) {
+		u64 new_tb = mftb() - vc->tb_offset_applied;
+		mtspr(SPRN_TBU40, new_tb);
+		if ((mftb() & 0xffffff) < (new_tb & 0xffffff)) {
+			new_tb += 0x1000000;
+			mtspr(SPRN_TBU40, new_tb);
+		}
+		vc->tb_offset_applied = 0;
+	}
+
+	local_paca->hmi_irqs++;
+
+	if (hmi_handle_debugtrig(NULL) >= 0) {
+		ret = 1;
+		goto out;
+	}
+
+	if (ppc_md.hmi_exception_early)
+		ppc_md.hmi_exception_early(NULL);
+
+out:
+	if (vc->tb_offset) {
+		u64 new_tb = mftb() + vc->tb_offset;
+		mtspr(SPRN_TBU40, new_tb);
+		if ((mftb() & 0xffffff) < (new_tb & 0xffffff)) {
+			new_tb += 0x1000000;
+			mtspr(SPRN_TBU40, new_tb);
+		}
+		vc->tb_offset_applied = vc->tb_offset;
+	}
+
+	return ret;
+}
+
+/*
+ * The following subcore HMI handling is all only for pre-POWER9 CPUs.
+ */
+
 /* Check if dynamic split is in force and return subcore size accordingly. */
 static inline int kvmppc_cur_subcore_size(void)
 {
-- 
2.23.0

Re: [PATCH v4 00/53] KVM: PPC: Book3S HV P9: entry/exit optimisations

[Michael Ellerman]

On Tue, 23 Nov 2021 19:51:38 +1000, Nicholas Piggin wrote:
> This reduces radix guest full entry/exit latency on POWER9 and POWER10
> by 2x.
> 
> Nested HV guests should see smaller improvements in their L1 entry/exit,
> but this is also combined with most L0 speedups also applying to nested
> entry. nginx localhost throughput test in a SMP nested guest is improved
> about 10% (in a direct guest it doesn't change much because it uses XIVE
> for IPIs) when L0 and L1 are patched.
> 
> [...]

Applied to powerpc/next.

[01/53] powerpc/64s: Remove WORT SPR from POWER9/10 (take 2)
        https://git.kernel.org/powerpc/c/f53884b1bf28497e9596cac8b44ef1d41bd6dfc5
[02/53] powerpc/64s: guard optional TIDR SPR with CPU ftr test
        https://git.kernel.org/powerpc/c/736df58fd5bcd02f811f7d474bbe02a35ffaa8f0
[03/53] KMV: PPC: Book3S HV P9: Use set_dec to set decrementer to host
        https://git.kernel.org/powerpc/c/5955c7469a73033f607ebd6d418058943fe13dd3
[04/53] KVM: PPC: Book3S HV P9: Use host timer accounting to avoid decrementer read
        https://git.kernel.org/powerpc/c/4ebbd075bcde7884e078d4360510b989f559bfec
[05/53] KVM: PPC: Book3S HV P9: Use large decrementer for HDEC
        https://git.kernel.org/powerpc/c/9581991a60817abe311c2581ae4554b28bfa32f1
[06/53] KVM: PPC: Book3S HV P9: Reduce mftb per guest entry/exit
        https://git.kernel.org/powerpc/c/34bf08a2079fffc7206a1ae93086ab8167e0afb6
[07/53] powerpc/time: add API for KVM to re-arm the host timer/decrementer
        https://git.kernel.org/powerpc/c/25aa145856cd0d94864bf501218be84a7c8062ae
[08/53] KVM: PPC: Book3S HV: POWER10 enable HAIL when running radix guests
        https://git.kernel.org/powerpc/c/eacc818864bb01828280f4d64334c4e5ae6a4daf
[09/53] powerpc/64s: Keep AMOR SPR a constant ~0 at runtime
        https://git.kernel.org/powerpc/c/46f9caf1a246a5c0622fa8cc7e673658e925f97e
[10/53] KVM: PPC: Book3S HV: Don't always save PMU for guest capable of nesting
        https://git.kernel.org/powerpc/c/d3c8a2d3740d93778ea102d4c781746d284177bf
[11/53] powerpc/64s: Always set PMU control registers to frozen/disabled when not in use
        https://git.kernel.org/powerpc/c/245ebf8e7380b3d84c0aac37fbfd9306b45a3a7a
[12/53] powerpc/64s: Implement PMU override command line option
        https://git.kernel.org/powerpc/c/0a4b4327ce867e3ac1b3ad15f4d2b686b516b3a2
[13/53] KVM: PPC: Book3S HV P9: Implement PMU save/restore in C
        https://git.kernel.org/powerpc/c/57dc0eed73caa31bfe36ce8fed234e214e37a5ae
[14/53] KVM: PPC: Book3S HV P9: Factor PMU save/load into context switch functions
        https://git.kernel.org/powerpc/c/401e1ae372673664465d45a86975c006dc6a488d
[15/53] KVM: PPC: Book3S HV P9: Demand fault PMU SPRs when marked not inuse
        https://git.kernel.org/powerpc/c/9d3ddb86d96d9f0314f3baaf0e37f987b40d3eee
[16/53] KVM: PPC: Book3S HV P9: Factor out yield_count increment
        https://git.kernel.org/powerpc/c/b1adcf57ceca7eab9bfdafc754802e05e634bfcc
[17/53] KVM: PPC: Book3S HV: CTRL SPR does not require read-modify-write
        https://git.kernel.org/powerpc/c/a1a19e1154e4e9c6c1136474cb040657b1c17817
[18/53] KVM: PPC: Book3S HV P9: Move SPRG restore to restore_p9_host_os_sprs
        https://git.kernel.org/powerpc/c/174a3ab633392859888fc1a5cff278d5546d8474
[19/53] KVM: PPC: Book3S HV P9: Reduce mtmsrd instructions required to save host SPRs
        https://git.kernel.org/powerpc/c/34e119c96b2b381278d1ddf6b1708678462daba4
[20/53] KVM: PPC: Book3S HV P9: Improve mtmsrd scheduling by delaying MSR[EE] disable
        https://git.kernel.org/powerpc/c/2251fbe76395e4d89c31099984714c5f1135f052
[21/53] KVM: PPC: Book3S HV P9: Add kvmppc_stop_thread to match kvmppc_start_thread
        https://git.kernel.org/powerpc/c/cf99dedb4b2d2a18e004b1c84852fffa810dc44c
[22/53] KVM: PPC: Book3S HV: Change dec_expires to be relative to guest timebase
        https://git.kernel.org/powerpc/c/3c1a4322bba79aad2d3f6f996b7e1c336bd909b3
[23/53] KVM: PPC: Book3S HV P9: Move TB updates
        https://git.kernel.org/powerpc/c/6547af3eba88e4806e853fee7547031b2cc6a560
[24/53] KVM: PPC: Book3S HV P9: Optimise timebase reads
        https://git.kernel.org/powerpc/c/cb2553a093093ae46cfaee31321bcedcd0312c5d
[25/53] KVM: PPC: Book3S HV P9: Avoid SPR scoreboard stalls
        https://git.kernel.org/powerpc/c/9a1e530bbbdaa2184993a7d7fc61d78871540ccd
[26/53] KVM: PPC: Book3S HV P9: Only execute mtSPR if the value changed
        https://git.kernel.org/powerpc/c/9dfe7aa7bc50556063c8658f59ad475131c09b65
[27/53] KVM: PPC: Book3S HV P9: Juggle SPR switching around
        https://git.kernel.org/powerpc/c/0f3b6c4851aef7a98b435c6f08b2c9c88165d254
[28/53] KVM: PPC: Book3S HV P9: Move vcpu register save/restore into functions
        https://git.kernel.org/powerpc/c/516b334210b831827e0491676625323f484275dd
[29/53] KVM: PPC: Book3S HV P9: Move host OS save/restore functions to built-in
        https://git.kernel.org/powerpc/c/aabcaf6ae2a0912898bd243f0aec0ce6853983fc
[30/53] KVM: PPC: Book3S HV P9: Move nested guest entry into its own function
        https://git.kernel.org/powerpc/c/08b3f08af583c01b3cfdc15bda68063c2a401512
[31/53] KVM: PPC: Book3S HV P9: Move remaining SPR and MSR access into low level entry
        https://git.kernel.org/powerpc/c/d5f480194577423731ee8413791a5486f26a95ab
[32/53] KVM: PPC: Book3S HV P9: Implement TM fastpath for guest entry/exit
        https://git.kernel.org/powerpc/c/3f9e2966d1b0dd81bcfaeb816335e0ddeedde3c1
[33/53] KVM: PPC: Book3S HV P9: Switch PMU to guest as late as possible
        https://git.kernel.org/powerpc/c/3e7b3379023dad2e78c3200373a6368f5d0ee599
[34/53] KVM: PPC: Book3S HV P9: Restrict DSISR canary workaround to processors that require it
        https://git.kernel.org/powerpc/c/d55b1eccc7aa14a1750aecf271806365478ca805
[35/53] KVM: PPC: Book3S HV P9: More SPR speed improvements
        https://git.kernel.org/powerpc/c/34e02d555d8fa36cc756a083de1eeb56edab0e00
[36/53] KVM: PPC: Book3S HV P9: Demand fault EBB facility registers
        https://git.kernel.org/powerpc/c/a3e18ca8ab6f7f2260978f0a3842845414d799c0
[37/53] KVM: PPC: Book3S HV P9: Demand fault TM facility registers
        https://git.kernel.org/powerpc/c/022ecb960c89faad42ff0b417a71d9255dd115a3
[38/53] KVM: PPC: Book3S HV P9: Use Linux SPR save/restore to manage some host SPRs
        https://git.kernel.org/powerpc/c/5236756d04454c7ce9f45e27b434d75b8d6f8759
[39/53] KVM: PPC: Book3S HV P9: Comment and fix MMU context switching code
        https://git.kernel.org/powerpc/c/cf3b16cfa6503b1fe5e680f9711262e6a51ef097
[40/53] KVM: PPC: Book3S HV P9: Test dawr_enabled() before saving host DAWR SPRs
        https://git.kernel.org/powerpc/c/9c75f65f3583b0cf467c378a1076f0b50bbc2fb1
[41/53] KVM: PPC: Book3S HV P9: Don't restore PSSCR if not needed
        https://git.kernel.org/powerpc/c/a089a6869e7f613a8d961ac65bafd127317e4c5c
[42/53] KVM: PPC: Book3S HV: Split P8 from P9 path guest vCPU TLB flushing
        https://git.kernel.org/powerpc/c/0ba0e5d5a691806cca3d4f290dcc61f656049872
[43/53] KVM: PPC: Book3S HV P9: Avoid tlbsync sequence on radix guest exit
        https://git.kernel.org/powerpc/c/d5c0e8332d82c04deee25dd6f28c5bbe84d49a73
[44/53] KVM: PPC: Book3S HV Nested: Avoid extra mftb() in nested entry
        https://git.kernel.org/powerpc/c/46dea77f790c1e7ab2e9f7452e34de0dc5da9b13
[45/53] KVM: PPC: Book3S HV P9: Improve mfmsr performance on entry
        https://git.kernel.org/powerpc/c/b49c65c5f9f1dac4ef1764578ad55bacf526eb38
[46/53] KVM: PPC: Book3S HV P9: Optimise hash guest SLB saving
        https://git.kernel.org/powerpc/c/241d1f19f0e5c257881a0661f201b51dc3e57f8c
[47/53] KVM: PPC: Book3S HV P9: Avoid changing MSR[RI] in entry and exit
        https://git.kernel.org/powerpc/c/f08cbf5c7d1f86f12143a1dce23740411b03a807
[48/53] KVM: PPC: Book3S HV P9: Add unlikely annotation for !mmu_ready
        https://git.kernel.org/powerpc/c/4c9a68914eab1f17f6c428c579ffd75c4448461e
[49/53] KVM: PPC: Book3S HV P9: Avoid cpu_in_guest atomics on entry and exit
        https://git.kernel.org/powerpc/c/434398ab5eed03dbc0075af9436e871712bfb45a
[50/53] KVM: PPC: Book3S HV P9: Remove most of the vcore logic
        https://git.kernel.org/powerpc/c/ecb6a7207f92e33c2b7a1271165ecf5d8f420bba
[51/53] KVM: PPC: Book3S HV P9: Tidy kvmppc_create_dtl_entry
        https://git.kernel.org/powerpc/c/617326ff01df30796d897895ebd18ce583c9b883
[52/53] KVM: PPC: Book3S HV P9: Stop using vc->dpdes
        https://git.kernel.org/powerpc/c/6398326b9ba182936bdc9d66475c09e39b701aa2
[53/53] KVM: PPC: Book3S HV P9: Remove subcore HMI handling
        https://git.kernel.org/powerpc/c/9c5a432a558105d6145b058fad78eb6fcf3d4c38

cheers