OpenCloudOS-Kernel/arch/powerpc/kvm
Paul Mackerras 6af27c847a KVM: PPC: Book3S HV: Streamline guest entry and exit
On entry to the guest, secondary threads now wait for the primary to
switch the MMU after loading up most of their state, rather than before.
This means that the secondary threads get into the guest sooner, in the
common case where the secondary threads get to kvmppc_hv_entry before
the primary thread.

On exit, the first thread out increments the exit count and interrupts
the other threads (to get them out of the guest) before saving most
of its state, rather than after.  That means that the other threads
exit sooner and means that the first thread doesn't spend so much
time waiting for the other threads at the point where the MMU gets
switched back to the host.

This pulls out the code that increments the exit count and interrupts
other threads into a separate function, kvmhv_commence_exit().
This also makes sure that r12 and vcpu->arch.trap are set correctly
in some corner cases.

Statistics from /sys/kernel/debug/kvm/vm*/vcpu*/timings show the
improvement.  Aggregating across vcpus for a guest with 32 vcpus,
8 threads/vcore, running on a POWER8, gives this before the change:

 rm_entry:     avg 4537.3ns (222 - 48444, 1068878 samples)
  rm_exit:     avg 4787.6ns (152 - 165490, 1010717 samples)
  rm_intr:     avg 1673.6ns (12 - 341304, 3818691 samples)

and this after the change:

 rm_entry:     avg 3427.7ns (232 - 68150, 1118921 samples)
  rm_exit:     avg 4716.0ns (12 - 150720, 1119477 samples)
  rm_intr:     avg 1614.8ns (12 - 522436, 3850432 samples)

showing a substantial reduction in the time spent per guest entry in
the real-mode guest entry code, and smaller reductions in the real
mode guest exit and interrupt handling times.  (The test was to start
the guest and boot Fedora 20 big-endian to the login prompt.)

Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Alexander Graf <agraf@suse.de>
2015-04-21 15:21:33 +02:00
..
Kconfig KVM: PPC: Book3S HV: Accumulate timing information for real-mode code 2015-04-21 15:21:31 +02:00
Makefile Here are the PPC and ARM changes for KVM, which I separated because 2014-08-07 11:35:30 -07:00
book3s.c kvmppc: Implement H_LOGICAL_CI_{LOAD,STORE} in KVM 2015-04-21 15:21:28 +02:00
book3s.h kvm: Fix page ageing bugs 2014-09-24 14:07:58 +02:00
book3s_32_mmu.c arch: powerpc: kvm: book3s_32_mmu.c: Remove unused function 2014-12-17 13:12:25 +01:00
book3s_32_mmu_host.c KVM: PPC: Book3S: Make magic page properly 4k mappable 2014-07-28 15:23:11 +02:00
book3s_32_sr.S KVM: PPC: book3s_pr: Simplify transitions between virtual and real mode 2011-09-25 19:52:29 +03:00
book3s_64_mmu.c KVM: PPC: Disable NX for old magic page using guests 2014-05-30 14:26:24 +02:00
book3s_64_mmu_host.c KVM: PPC: Book3S: Make magic page properly 4k mappable 2014-07-28 15:23:11 +02:00
book3s_64_mmu_hv.c KVM: PPC: Book3S HV: Create debugfs file for each guest's HPT 2015-04-21 15:21:31 +02:00
book3s_64_slb.S KVM: PPC: Book3S PR: Rework SLB switching code 2014-05-30 14:26:30 +02:00
book3s_64_vio.c ppc: kvm: use anon_inode_getfd() with O_CLOEXEC flag 2013-08-26 13:19:56 +03:00
book3s_64_vio_hv.c KVM: PPC: Book3S: Introduce hypervisor call H_GET_TCE 2014-03-26 23:34:27 +11:00
book3s_emulate.c KVM: PPC: PR: Handle FSCR feature deselects 2014-07-31 10:23:46 +02:00
book3s_exports.c KVM: PPC: Make shared struct aka magic page guest endian 2014-05-30 14:26:21 +02:00
book3s_hv.c KVM: PPC: Book3S HV: Use bitmap of active threads rather than count 2015-04-21 15:21:33 +02:00
book3s_hv_builtin.c KVM: PPC: Book3S HV: Use bitmap of active threads rather than count 2015-04-21 15:21:33 +02:00
book3s_hv_interrupts.S powerpc/kvm: Create proper names for the kvm_host_state PMU fields 2014-12-29 15:45:55 +11:00
book3s_hv_ras.c KVM: PPC: Book3S HV: Remove code for PPC970 processors 2014-12-17 13:44:03 +01:00
book3s_hv_rm_mmu.c KVM: PPC: Book3S HV: Add helpers for lock/unlock hpte 2015-04-21 15:21:29 +02:00
book3s_hv_rm_xics.c KVM: PPC: Book3S HV: Add ICP real mode counters 2015-04-21 15:21:30 +02:00
book3s_hv_rmhandlers.S KVM: PPC: Book3S HV: Streamline guest entry and exit 2015-04-21 15:21:33 +02:00
book3s_interrupts.S KVM: PPC: Book3S PR: Fix ABIv2 on LE 2014-07-28 15:22:15 +02:00
book3s_mmu_hpte.c kvm: powerpc: book3s: pr: move PR related tracepoints to a separate header 2013-10-17 15:36:22 +02:00
book3s_paired_singles.c arch: powerpc: kvm: book3s_paired_singles.c: Remove unused function 2014-12-17 13:13:29 +01:00
book3s_pr.c arch: powerpc: kvm: book3s_pr.c: Remove unused function 2014-12-17 13:13:16 +01:00
book3s_pr_papr.c kvmppc: Implement H_LOGICAL_CI_{LOAD,STORE} in KVM 2015-04-21 15:21:28 +02:00
book3s_rmhandlers.S KVM: PPC: Book3S PR: Fix ABIv2 on LE 2014-07-28 15:22:15 +02:00
book3s_rtas.c KVM: PPC: RTAS: Do byte swaps explicitly 2014-07-07 23:17:20 +02:00
book3s_segment.S KVM: PPC: Book3S PR: Handle Facility interrupt and FSCR 2014-05-30 14:26:22 +02:00
book3s_xics.c KVM: PPC: Book3S HV: Add ICP real mode counters 2015-04-21 15:21:30 +02:00
book3s_xics.h KVM: PPC: Book3S HV: Add ICP real mode counters 2015-04-21 15:21:30 +02:00
booke.c kvm: add halt_poll_ns module parameter 2015-02-06 13:08:37 +01:00
booke.h KVM: PPC: Book3e: Add AltiVec support 2014-09-22 10:11:32 +02:00
booke_emulate.c KVM: PPC: BOOKE: Emulate debug registers and exception 2014-09-22 10:11:33 +02:00
booke_interrupts.S KVM: PPC: Remove 440 support 2014-07-28 15:23:15 +02:00
bookehv_interrupts.S powerpc/kvm: common sw breakpoint instr across ppc 2014-09-22 10:11:36 +02:00
e500.c 3.19 changes for KVM: 2014-12-18 16:05:28 -08:00
e500.h KVM: PPC: e500mc: Add support for single threaded vcpus on e6500 core 2014-09-22 10:11:35 +02:00
e500_emulate.c KVM: PPC: Book3e: Add AltiVec support 2014-09-22 10:11:32 +02:00
e500_mmu.c KVM: PPC: e500: Fix bad address type in deliver_tlb_misss() 2014-01-27 16:00:54 +01:00
e500_mmu_host.c treewide: fix typo in printk and Kconfig 2014-11-20 14:56:11 +01:00
e500_mmu_host.h KVM: PPC: E500: Make clear_tlb_refs and clear_tlb1_bitmap static 2013-01-24 19:23:33 +01:00
e500mc.c powerpc: Replace __get_cpu_var uses 2014-11-03 12:12:32 +11:00
emulate.c KVM: PPC: Pass enum to kvmppc_get_last_inst 2014-09-22 10:11:36 +02:00
emulate_loadstore.c KVM: PPC: Pass enum to kvmppc_get_last_inst 2014-09-22 10:11:36 +02:00
fpu.S powerpc: Remove fpscr use from [kvm_]cvt_{fd,df} 2010-09-02 14:07:32 +10:00
irq.h KVM: PPC: Book3S: Add API for in-kernel XICS emulation 2013-05-02 15:28:36 +02:00
mpic.c kvm/ppc/mpic: drop unused IRQ_testbit 2015-04-08 10:46:58 +02:00
powerpc.c KVM: PPC: Book3S HV: Add fast real-mode H_RANDOM implementation. 2015-04-21 15:21:29 +02:00
timing.c KVM: PPC: Remove DCR handling 2014-07-28 19:29:15 +02:00
timing.h KVM: PPC: Remove DCR handling 2014-07-28 19:29:15 +02:00
trace.h kvm: powerpc: booke: Move booke related tracepoints to separate header 2013-10-17 15:37:16 +02:00
trace_book3s.h KVM: PPC: Book3S HV: Tracepoints for KVM HV guest interactions 2014-12-17 13:29:27 +01:00
trace_booke.h KVM: PPC: BookE: Improve irq inject tracepoint 2014-12-15 13:27:23 +01:00
trace_hv.h KVM: PPC: Book3S HV: Tracepoints for KVM HV guest interactions 2014-12-17 13:29:27 +01:00
trace_pr.h KVM: PPC: Book3S HV: Tracepoints for KVM HV guest interactions 2014-12-17 13:29:27 +01:00