mirror of https://gitee.com/openkylin/linux.git
111 Commits
Author | SHA1 | Message | Date |
---|---|---|---|
Paolo Bonzini | f781951299 |
kvm: add halt_poll_ns module parameter
This patch introduces a new module parameter for the KVM module; when it is present, KVM attempts a bit of polling on every HLT before scheduling itself out via kvm_vcpu_block. This parameter helps a lot for latency-bound workloads---in particular I tested it with O_DSYNC writes with a battery-backed disk in the host. In this case, writes are fast (because the data doesn't have to go all the way to the platters) but they cannot be merged by either the host or the guest. KVM's performance here is usually around 30% of bare metal, or 50% if you use cache=directsync or cache=writethrough (these parameters avoid that the guest sends pointless flush requests, and at the same time they are not slow because of the battery-backed cache). The bad performance happens because on every halt the host CPU decides to halt itself too. When the interrupt comes, the vCPU thread is then migrated to a new physical CPU, and in general the latency is horrible because the vCPU thread has to be scheduled back in. With this patch performance reaches 60-65% of bare metal and, more important, 99% of what you get if you use idle=poll in the guest. This means that the tunable gets rid of this particular bottleneck, and more work can be done to improve performance in the kernel or QEMU. Of course there is some price to pay; every time an otherwise idle vCPUs is interrupted by an interrupt, it will poll unnecessarily and thus impose a little load on the host. The above results were obtained with a mostly random value of the parameter (500000), and the load was around 1.5-2.5% CPU usage on one of the host's core for each idle guest vCPU. The patch also adds a new stat, /sys/kernel/debug/kvm/halt_successful_poll, that can be used to tune the parameter. It counts how many HLT instructions received an interrupt during the polling period; each successful poll avoids that Linux schedules the VCPU thread out and back in, and may also avoid a likely trip to C1 and back for the physical CPU. While the VM is idle, a Linux 4 VCPU VM halts around 10 times per second. Of these halts, almost all are failed polls. During the benchmark, instead, basically all halts end within the polling period, except a more or less constant stream of 50 per second coming from vCPUs that are not running the benchmark. The wasted time is thus very low. Things may be slightly different for Windows VMs, which have a ~10 ms timer tick. The effect is also visible on Marcelo's recently-introduced latency test for the TSC deadline timer. Though of course a non-RT kernel has awful latency bounds, the latency of the timer is around 8000-10000 clock cycles compared to 20000-120000 without setting halt_poll_ns. For the TSC deadline timer, thus, the effect is both a smaller average latency and a smaller variance. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> |
|
James Hogan | f798217dfd |
KVM: MIPS: Don't leak FPU/DSP to guest
The FPU and DSP are enabled via the CP0 Status CU1 and MX bits by kvm_mips_set_c0_status() on a guest exit, presumably in case there is active state that needs saving if pre-emption occurs. However neither of these bits are cleared again when returning to the guest. This effectively gives the guest access to the FPU/DSP hardware after the first guest exit even though it is not aware of its presence, allowing FP instructions in guest user code to intermittently actually execute instead of trapping into the guest OS for emulation. It will then read & manipulate the hardware FP registers which technically belong to the user process (e.g. QEMU), or are stale from another user process. It can also crash the guest OS by causing an FP exception, for which a guest exception handler won't have been registered. First lets save and disable the FPU (and MSA) state with lose_fpu(1) before entering the guest. This simplifies the problem, especially for when guest FPU/MSA support is added in the future, and prevents FR=1 FPU state being live when the FR bit gets cleared for the guest, which according to the architecture causes the contents of the FPU and vector registers to become UNPREDICTABLE. We can then safely remove the enabling of the FPU in kvm_mips_set_c0_status(), since there should never be any active FPU or MSA state to save at pre-emption, which should plug the FPU leak. DSP state is always live rather than being lazily restored, so for that it is simpler to just clear the MX bit again when re-entering the guest. Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Sanjay Lal <sanjayl@kymasys.com> Cc: Gleb Natapov <gleb@kernel.org> Cc: kvm@vger.kernel.org Cc: linux-mips@linux-mips.org Cc: <stable@vger.kernel.org> # v3.10+: 044f0f03eca0: MIPS: KVM: Deliver guest interrupts Cc: <stable@vger.kernel.org> # v3.10+ Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> |
|
James Hogan | c4c6f2cad9 |
KVM: MIPS: Disable HTW while in guest
Ensure any hardware page table walker (HTW) is disabled while in KVM guest mode, as KVM doesn't yet set up hardware page table walking for guest mappings so the wrong mappings would get loaded, resulting in the guest hanging or crashing once it reaches userland. The HTW is disabled and re-enabled around the call to __kvm_mips_vcpu_run() which does the initial switch into guest mode and the final switch out of guest context. Additionally it is enabled for the duration of guest exits (i.e. kvm_mips_handle_exit()), getting disabled again before returning back to guest or host. In all cases the HTW is only disabled in normal kernel mode while interrupts are disabled, so that the HTW doesn't get left disabled if the process is preempted. Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Markos Chandras <markos.chandras@imgtec.com> Cc: Gleb Natapov <gleb@kernel.org> Cc: kvm@vger.kernel.org Cc: linux-mips@linux-mips.org Cc: <stable@vger.kernel.org> # v3.17+ Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> |
|
Dominik Dingel | 31928aa586 |
KVM: remove unneeded return value of vcpu_postcreate
The return value of kvm_arch_vcpu_postcreate is not checked in its caller. This is okay, because only x86 provides vcpu_postcreate right now and it could only fail if vcpu_load failed. But that is not possible during KVM_CREATE_VCPU (kvm_arch_vcpu_load is void, too), so just get rid of the unchecked return value. Signed-off-by: Dominik Dingel <dingel@linux.vnet.ibm.com> Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> |
|
Radim Krčmář | 13a34e067e |
KVM: remove garbage arg to *hardware_{en,dis}able
In the beggining was on_each_cpu(), which required an unused argument to kvm_arch_ops.hardware_{en,dis}able, but this was soon forgotten. Remove unnecessary arguments that stem from this. Signed-off-by: Radim KrÄmář <rkrcmar@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> |
|
Radim Krčmář | 0865e636ae |
KVM: static inline empty kvm_arch functions
Using static inline is going to save few bytes and cycles. For example on powerpc, the difference is 700 B after stripping. (5 kB before) This patch also deals with two overlooked empty functions: kvm_arch_flush_shadow was not removed from arch/mips/kvm/mips.c |
|
Radim Krčmář | e790d9ef64 |
KVM: add kvm_arch_sched_in
Introduce preempt notifiers for architecture specific code. Advantage over creating a new notifier in every arch is slightly simpler code and guaranteed call order with respect to kvm_sched_in. Signed-off-by: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> |
|
Paolo Bonzini | cc568ead3c |
Patch queue for ppc - 2014-08-01
Highlights in this release include: - BookE: Rework instruction fetch, not racy anymore now - BookE HV: Fix ONE_REG accessors for some in-hardware registers - Book3S: Good number of LE host fixes, enable HV on LE - Book3S: Some misc bug fixes - Book3S HV: Add in-guest debug support - Book3S HV: Preload cache lines on context switch - Remove 440 support Alexander Graf (31): KVM: PPC: Book3s PR: Disable AIL mode with OPAL KVM: PPC: Book3s HV: Fix tlbie compile error KVM: PPC: Book3S PR: Handle hyp doorbell exits KVM: PPC: Book3S PR: Fix ABIv2 on LE KVM: PPC: Book3S PR: Fix sparse endian checks PPC: Add asm helpers for BE 32bit load/store KVM: PPC: Book3S HV: Make HTAB code LE host aware KVM: PPC: Book3S HV: Access guest VPA in BE KVM: PPC: Book3S HV: Access host lppaca and shadow slb in BE KVM: PPC: Book3S HV: Access XICS in BE KVM: PPC: Book3S HV: Fix ABIv2 on LE KVM: PPC: Book3S HV: Enable for little endian hosts KVM: PPC: Book3S: Move vcore definition to end of kvm_arch struct KVM: PPC: Deflect page write faults properly in kvmppc_st KVM: PPC: Book3S: Stop PTE lookup on write errors KVM: PPC: Book3S: Add hack for split real mode KVM: PPC: Book3S: Make magic page properly 4k mappable KVM: PPC: Remove 440 support KVM: Rename and add argument to check_extension KVM: Allow KVM_CHECK_EXTENSION on the vm fd KVM: PPC: Book3S: Provide different CAPs based on HV or PR mode KVM: PPC: Implement kvmppc_xlate for all targets KVM: PPC: Move kvmppc_ld/st to common code KVM: PPC: Remove kvmppc_bad_hva() KVM: PPC: Use kvm_read_guest in kvmppc_ld KVM: PPC: Handle magic page in kvmppc_ld/st KVM: PPC: Separate loadstore emulation from priv emulation KVM: PPC: Expose helper functions for data/inst faults KVM: PPC: Remove DCR handling KVM: PPC: HV: Remove generic instruction emulation KVM: PPC: PR: Handle FSCR feature deselects Alexey Kardashevskiy (1): KVM: PPC: Book3S: Fix LPCR one_reg interface Aneesh Kumar K.V (4): KVM: PPC: BOOK3S: PR: Fix PURR and SPURR emulation KVM: PPC: BOOK3S: PR: Emulate virtual timebase register KVM: PPC: BOOK3S: PR: Emulate instruction counter KVM: PPC: BOOK3S: HV: Update compute_tlbie_rb to handle 16MB base page Anton Blanchard (2): KVM: PPC: Book3S HV: Fix ABIv2 indirect branch issue KVM: PPC: Assembly functions exported to modules need _GLOBAL_TOC() Bharat Bhushan (10): kvm: ppc: bookehv: Added wrapper macros for shadow registers kvm: ppc: booke: Use the shared struct helpers of SRR0 and SRR1 kvm: ppc: booke: Use the shared struct helpers of SPRN_DEAR kvm: ppc: booke: Add shared struct helpers of SPRN_ESR kvm: ppc: booke: Use the shared struct helpers for SPRN_SPRG0-7 kvm: ppc: Add SPRN_EPR get helper function kvm: ppc: bookehv: Save restore SPRN_SPRG9 on guest entry exit KVM: PPC: Booke-hv: Add one reg interface for SPRG9 KVM: PPC: Remove comment saying SPRG1 is used for vcpu pointer KVM: PPC: BOOKEHV: rename e500hv_spr to bookehv_spr Michael Neuling (1): KVM: PPC: Book3S HV: Add H_SET_MODE hcall handling Mihai Caraman (8): KVM: PPC: e500mc: Enhance tlb invalidation condition on vcpu schedule KVM: PPC: e500: Fix default tlb for victim hint KVM: PPC: e500: Emulate power management control SPR KVM: PPC: e500mc: Revert "add load inst fixup" KVM: PPC: Book3e: Add TLBSEL/TSIZE defines for MAS0/1 KVM: PPC: Book3s: Remove kvmppc_read_inst() function KVM: PPC: Allow kvmppc_get_last_inst() to fail KVM: PPC: Bookehv: Get vcpu's last instruction for emulation Paul Mackerras (4): KVM: PPC: Book3S: Controls for in-kernel sPAPR hypercall handling KVM: PPC: Book3S: Allow only implemented hcalls to be enabled or disabled KVM: PPC: Book3S PR: Take SRCU read lock around RTAS kvm_read_guest() call KVM: PPC: Book3S: Make kvmppc_ld return a more accurate error indication Stewart Smith (2): Split out struct kvmppc_vcore creation to separate function Use the POWER8 Micro Partition Prefetch Engine in KVM HV on POWER8 -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.19 (GNU/Linux) iQIcBAABAgAGBQJT21skAAoJECszeR4D/txgeFEP/AzJopN7s//W33CfyBqURHXp XALCyAw+S67gtcaTZbxomcG1xuT8Lj9WEw28iz3rCtAnJwIxsY63xrI1nXMzTaI2 p1rC0ai5Qy+nlEbd6L78spZy/Nzh8DFYGWx78iUSO1mYD8xywJwtoiBA539pwp8j 8N+mgn61Hwhv31bKtsZlmzXymVr/jbTp5LVuxsBLJwD2lgT49g+4uBnX2cG/iXkg Rzbh7LxoNNXrSPI8sYmTWu/81aeXteeX70ja6DHuV5dWLNTuAXJrh5EUfeAZqBrV aYcLWUYmIyB87txNmt6ZGVar2p3jr2Xhb9mKx+EN4dbehblanLc1PUqlHd0q3dKc Nt60ByqpZn+qDAK86dShSZLEe+GT3lovvE76CqVXD4Er+OUEkc9JoxhN1cof/Gb0 o6uwZ2isXHRdGoZx5vb4s3UTOlwZGtoL/CyY/HD/ujYDSURkCGbxLj3kkecSY8ut QdDAWsC15BwsHtKLr5Zwjp2w+0eGq2QJgfvO0zqWFiz9k33SCBCUpwluFeqh27Hi aR5Wir3j+MIw9G8XlYlDJWYfi0h/SZ4G7hh7jSu26NBNBzQsDa8ow/cLzdMhdUwH OYSaeqVk5wiRb9to1uq1NQWPA0uRAx3BSjjvr9MCGRqmvn+FV5nj637YWUT+53Hi aSvg/U2npghLPPG2cihu =JuLr -----END PGP SIGNATURE----- Merge tag 'signed-kvm-ppc-next' of git://github.com/agraf/linux-2.6 into kvm Patch queue for ppc - 2014-08-01 Highlights in this release include: - BookE: Rework instruction fetch, not racy anymore now - BookE HV: Fix ONE_REG accessors for some in-hardware registers - Book3S: Good number of LE host fixes, enable HV on LE - Book3S: Some misc bug fixes - Book3S HV: Add in-guest debug support - Book3S HV: Preload cache lines on context switch - Remove 440 support Alexander Graf (31): KVM: PPC: Book3s PR: Disable AIL mode with OPAL KVM: PPC: Book3s HV: Fix tlbie compile error KVM: PPC: Book3S PR: Handle hyp doorbell exits KVM: PPC: Book3S PR: Fix ABIv2 on LE KVM: PPC: Book3S PR: Fix sparse endian checks PPC: Add asm helpers for BE 32bit load/store KVM: PPC: Book3S HV: Make HTAB code LE host aware KVM: PPC: Book3S HV: Access guest VPA in BE KVM: PPC: Book3S HV: Access host lppaca and shadow slb in BE KVM: PPC: Book3S HV: Access XICS in BE KVM: PPC: Book3S HV: Fix ABIv2 on LE KVM: PPC: Book3S HV: Enable for little endian hosts KVM: PPC: Book3S: Move vcore definition to end of kvm_arch struct KVM: PPC: Deflect page write faults properly in kvmppc_st KVM: PPC: Book3S: Stop PTE lookup on write errors KVM: PPC: Book3S: Add hack for split real mode KVM: PPC: Book3S: Make magic page properly 4k mappable KVM: PPC: Remove 440 support KVM: Rename and add argument to check_extension KVM: Allow KVM_CHECK_EXTENSION on the vm fd KVM: PPC: Book3S: Provide different CAPs based on HV or PR mode KVM: PPC: Implement kvmppc_xlate for all targets KVM: PPC: Move kvmppc_ld/st to common code KVM: PPC: Remove kvmppc_bad_hva() KVM: PPC: Use kvm_read_guest in kvmppc_ld KVM: PPC: Handle magic page in kvmppc_ld/st KVM: PPC: Separate loadstore emulation from priv emulation KVM: PPC: Expose helper functions for data/inst faults KVM: PPC: Remove DCR handling KVM: PPC: HV: Remove generic instruction emulation KVM: PPC: PR: Handle FSCR feature deselects Alexey Kardashevskiy (1): KVM: PPC: Book3S: Fix LPCR one_reg interface Aneesh Kumar K.V (4): KVM: PPC: BOOK3S: PR: Fix PURR and SPURR emulation KVM: PPC: BOOK3S: PR: Emulate virtual timebase register KVM: PPC: BOOK3S: PR: Emulate instruction counter KVM: PPC: BOOK3S: HV: Update compute_tlbie_rb to handle 16MB base page Anton Blanchard (2): KVM: PPC: Book3S HV: Fix ABIv2 indirect branch issue KVM: PPC: Assembly functions exported to modules need _GLOBAL_TOC() Bharat Bhushan (10): kvm: ppc: bookehv: Added wrapper macros for shadow registers kvm: ppc: booke: Use the shared struct helpers of SRR0 and SRR1 kvm: ppc: booke: Use the shared struct helpers of SPRN_DEAR kvm: ppc: booke: Add shared struct helpers of SPRN_ESR kvm: ppc: booke: Use the shared struct helpers for SPRN_SPRG0-7 kvm: ppc: Add SPRN_EPR get helper function kvm: ppc: bookehv: Save restore SPRN_SPRG9 on guest entry exit KVM: PPC: Booke-hv: Add one reg interface for SPRG9 KVM: PPC: Remove comment saying SPRG1 is used for vcpu pointer KVM: PPC: BOOKEHV: rename e500hv_spr to bookehv_spr Michael Neuling (1): KVM: PPC: Book3S HV: Add H_SET_MODE hcall handling Mihai Caraman (8): KVM: PPC: e500mc: Enhance tlb invalidation condition on vcpu schedule KVM: PPC: e500: Fix default tlb for victim hint KVM: PPC: e500: Emulate power management control SPR KVM: PPC: e500mc: Revert "add load inst fixup" KVM: PPC: Book3e: Add TLBSEL/TSIZE defines for MAS0/1 KVM: PPC: Book3s: Remove kvmppc_read_inst() function KVM: PPC: Allow kvmppc_get_last_inst() to fail KVM: PPC: Bookehv: Get vcpu's last instruction for emulation Paul Mackerras (4): KVM: PPC: Book3S: Controls for in-kernel sPAPR hypercall handling KVM: PPC: Book3S: Allow only implemented hcalls to be enabled or disabled KVM: PPC: Book3S PR: Take SRCU read lock around RTAS kvm_read_guest() call KVM: PPC: Book3S: Make kvmppc_ld return a more accurate error indication Stewart Smith (2): Split out struct kvmppc_vcore creation to separate function Use the POWER8 Micro Partition Prefetch Engine in KVM HV on POWER8 Conflicts: Documentation/virtual/kvm/api.txt |
|
Linus Torvalds | 8533ce7271 |
These are the x86, MIPS and s390 changes; PPC and ARM will come in a
few days. MIPS and s390 have little going on this release; just bugfixes, some small, some larger. The highlights for x86 are nested VMX improvements (Jan Kiszka), optimizations for old processor (up to Nehalem, by me and Bandan Das), and a lot of x86 emulator bugfixes (Nadav Amit). Stephen Rothwell reported a trivial conflict with the tracing branch. -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iQIcBAABAgAGBQJT300XAAoJEBvWZb6bTYby3V8QAJz+XyajnhJ8wH55Vxczz22L i2gtUGmBLhEXsBcaVKO4BBfek88lLzg0SGLjfW5wCMQmKtxVlrwTCXNkBoPGjapd NwHtWkMKym44PDhRovn7zkSumkxC43uFIBR/ebrhP6Bvhh9s+MnkQUxfw9ILB+YV EeKyEG8sSgxFCciuHbp3mIXpDcO6r/ldy6I7009OdyhLoMY+Kvmk7kRe9wtAivdg CGJi60QvGOn2RGRPOCEtF6UWr8Ae8fe1t84o0hkXPv/j3jtabzAatXKJa4dYNbIs 7Mp4NQpxaGV6rq3WCYVeZRxGs+UReGDAS3Il4Z8C9eTOTooSfxdVr8acpM8PY6I8 UmLT6ECLGycc4ELXrETtR+QLmiXACyJqyVxz4aiLV3kWSWfamKD3hBeQK9NizNcE VoPDl+PyISvR1tW4KstBuzfUWAEXi+gO78cqqFr/VW6cl7HKpA1DFQaPfGkYKDae 2CPwcLwI5/M6RtSgkyXTkEqNZLc2BjldqSeM1lmWjhZVW56X2iqePUL46Vab3Yvt U+sELtwEE560NLN3hbaHUsLR1tcUix5w8vTzcXPxgoHQBszHCcAZTWd1XHulr64F rp/cangqtkPKcu5j1mNhQs38oLjHI1MUsbQrqFoD4tmHjQ75iXHRFzYGoIVKXyHG AnGbQzJzBcdAANhm3LW0 =UXxV -----END PGP SIGNATURE----- Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm Pull KVM changes from Paolo Bonzini: "These are the x86, MIPS and s390 changes; PPC and ARM will come in a few days. MIPS and s390 have little going on this release; just bugfixes, some small, some larger. The highlights for x86 are nested VMX improvements (Jan Kiszka), optimizations for old processor (up to Nehalem, by me and Bandan Das), and a lot of x86 emulator bugfixes (Nadav Amit). Stephen Rothwell reported a trivial conflict with the tracing branch" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (104 commits) x86/kvm: Resolve shadow warnings in macro expansion KVM: s390: rework broken SIGP STOP interrupt handling KVM: x86: always exit on EOIs for interrupts listed in the IOAPIC redir table KVM: vmx: remove duplicate vmx_mpx_supported() prototype KVM: s390: Fix memory leak on busy SIGP stop x86/kvm: Resolve shadow warning from min macro kvm: Resolve missing-field-initializers warnings Replace NR_VMX_MSR with its definition KVM: x86: Assertions to check no overrun in MSR lists KVM: x86: set rflags.rf during fault injection KVM: x86: Setting rflags.rf during rep-string emulation KVM: x86: DR6/7.RTM cannot be written KVM: nVMX: clean up nested_release_vmcs12 and code around it KVM: nVMX: fix lifetime issues for vmcs02 KVM: x86: Defining missing x86 vectors KVM: x86: emulator injects #DB when RFLAGS.RF is set KVM: x86: Cleanup of rflags.rf cleaning KVM: x86: Clear rflags.rf on emulated instructions KVM: x86: popf emulation should not change RF KVM: x86: Clearing rflags.rf upon skipped emulated instruction ... |
|
Alexander Graf | 784aa3d7fb |
KVM: Rename and add argument to check_extension
In preparation to make the check_extension function available to VM scope we add a struct kvm * argument to the function header and rename the function accordingly. It will still be called from the /dev/kvm fd, but with a NULL argument for struct kvm *. Signed-off-by: Alexander Graf <agraf@suse.de> Acked-by: Paolo Bonzini <pbonzini@redhat.com> |
|
Deng-Cheng Zhu | d7d5b05faf |
MIPS: KVM: Rename files to remove the prefix "kvm_" and "kvm_mips_"
Since all the files are in arch/mips/kvm/, there's no need of the prefixes "kvm_" and "kvm_mips_". Reviewed-by: James Hogan <james.hogan@imgtec.com> Signed-off-by: Deng-Cheng Zhu <dengcheng.zhu@imgtec.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> |