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2013-06-12KVM: x86: handle idiv overflow at kvm_write_tscMarcelo Tosatti
Its possible that idivl overflows (due to large delta stored in usdiff, valid scenario). Create an exception handler to catch the overflow exception (division by zero is protected by vcpu->arch.virtual_tsc_khz check), and interpret it accordingly (delta is larger than USEC_PER_SEC). Fixes https://bugzilla.redhat.com/show_bug.cgi?id=969644 Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-06-05KVM: MMU: reduce KVM_REQ_MMU_RELOAD when root page is zappedGleb Natapov
Quote Gleb's mail: | why don't we check for sp->role.invalid in | kvm_mmu_prepare_zap_page before calling kvm_reload_remote_mmus()? and | Actually we can add check for is_obsolete_sp() there too since | kvm_mmu_invalidate_all_pages() already calls kvm_reload_remote_mmus() | after incrementing mmu_valid_gen. [ Xiao: add some comments and the check of is_obsolete_sp() ] Signed-off-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-06-05KVM: MMU: reclaim the zapped-obsolete page firstXiao Guangrong
As Marcelo pointed out that | "(retention of large number of pages while zapping) | can be fatal, it can lead to OOM and host crash" We introduce a list, kvm->arch.zapped_obsolete_pages, to link all the pages which are deleted from the mmu cache but not actually freed. When page reclaiming is needed, we always zap this kind of pages first. Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-06-05KVM: MMU: collapse TLB flushes when zap all pagesXiao Guangrong
kvm_zap_obsolete_pages uses lock-break technique to zap pages, it will flush tlb every time when it does lock-break We can reload mmu on all vcpus after updating the generation number so that the obsolete pages are not used on any vcpus, after that we do not need to flush tlb when obsolete pages are zapped It will do kvm_mmu_prepare_zap_page many times and use one kvm_mmu_commit_zap_page to collapse tlb flush, the side-effects is that causes obsolete pages unlinked from active_list but leave on hash-list, so we add the comment around the hash list walker Note: kvm_mmu_commit_zap_page is still needed before free the pages since other vcpus may be doing locklessly shadow page walking Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-06-05KVM: MMU: zap pages in batchXiao Guangrong
Zap at lease 10 pages before releasing mmu-lock to reduce the overload caused by requiring lock After the patch, kvm_zap_obsolete_pages can forward progress anyway, so update the comments [ It improves the case 0.6% ~ 1% that do kernel building meanwhile read PCI ROM. ] Note: i am not sure that "10" is the best speculative value, i just guessed that '10' can make vcpu do not spend long time on kvm_zap_obsolete_pages and do not cause mmu-lock too hungry. Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-06-05KVM: MMU: do not reuse the obsolete pageXiao Guangrong
The obsolete page will be zapped soon, do not reuse it to reduce future page fault Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-06-05KVM: MMU: add tracepoint for kvm_mmu_invalidate_all_pagesXiao Guangrong
It is good for debug and development Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-06-05KVM: MMU: show mmu_valid_gen in shadow page related tracepointsXiao Guangrong
Show sp->mmu_valid_gen Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-06-05KVM: x86: use the fast way to invalidate all pagesXiao Guangrong
Replace kvm_mmu_zap_all by kvm_mmu_invalidate_zap_all_pages Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-06-05KVM: MMU: fast invalidate all pagesXiao Guangrong
The current kvm_mmu_zap_all is really slow - it is holding mmu-lock to walk and zap all shadow pages one by one, also it need to zap all guest page's rmap and all shadow page's parent spte list. Particularly, things become worse if guest uses more memory or vcpus. It is not good for scalability In this patch, we introduce a faster way to invalidate all shadow pages. KVM maintains a global mmu invalid generation-number which is stored in kvm->arch.mmu_valid_gen and every shadow page stores the current global generation-number into sp->mmu_valid_gen when it is created When KVM need zap all shadow pages sptes, it just simply increase the global generation-number then reload root shadow pages on all vcpus. Vcpu will create a new shadow page table according to current kvm's generation-number. It ensures the old pages are not used any more. Then the obsolete pages (sp->mmu_valid_gen != kvm->arch.mmu_valid_gen) are zapped by using lock-break technique Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-06-05KVM: MMU: drop unnecessary kvm_reload_remote_mmusXiao Guangrong
It is the responsibility of kvm_mmu_zap_all that keeps the consistent of mmu and tlbs. And it is also unnecessary after zap all mmio sptes since no mmio spte exists on root shadow page and it can not be cached into tlb Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-06-05KVM: x86: drop calling kvm_mmu_zap_all in emulator_fix_hypercallXiao Guangrong
Quote Gleb's mail: | Back then kvm->lock protected memslot access so code like: | | mutex_lock(&vcpu->kvm->lock); | kvm_mmu_zap_all(vcpu->kvm); | mutex_unlock(&vcpu->kvm->lock); | | which is what 7aa81cc0 does was enough to guaranty that no vcpu will | run while code is patched. This is no longer the case and | mutex_lock(&vcpu->kvm->lock); is gone from that code path long time ago, | so now kvm_mmu_zap_all() there is useless and the code is incorrect. So we drop it and it will be fixed later Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-05-21KVM: x86 emulator: convert XADD to fastopAvi Kivity
Signed-off-by: Avi Kivity <avi.kivity@gmail.com> Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-05-21KVM: x86 emulator: drop unused old-style inline emulationAvi Kivity
Signed-off-by: Avi Kivity <avi.kivity@gmail.com> Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-05-21KVM: x86 emulator: convert DIV/IDIV to fastopAvi Kivity
Since DIV and IDIV can generate exceptions, we need an additional output parameter indicating whether an execption has occured. To avoid increasing register pressure on i386, we use %rsi, which is already allocated for the fastop code pointer. Gleb: added comment about fop usage as exception indication. Signed-off-by: Avi Kivity <avi.kivity@gmail.com> Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-05-21KVM: x86 emulator: convert single-operand MUL/IMUL to fastopAvi Kivity
Signed-off-by: Avi Kivity <avi.kivity@gmail.com> Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-05-21KVM: x86 emulator: Switch fastop src operand to RDXAvi Kivity
This makes OpAccHi useful. Signed-off-by: Avi Kivity <avi.kivity@gmail.com> Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-05-21KVM: x86 emulator: switch MUL/DIV to DstXaccAvi Kivity
Signed-off-by: Avi Kivity <avi.kivity@gmail.com> Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-05-21KVM: x86 emulator: decode extended accumulator explicityAvi Kivity
Single-operand MUL and DIV access an extended accumulator: AX for byte instructions, and DX:AX, EDX:EAX, or RDX:RAX for larger-sized instructions. Add support for fetching the extended accumulator. In order not to change things too much, RDX is loaded into Src2, which is already loaded by fastop(). This avoids increasing register pressure on i386. Gleb: disable src writeback for ByteOp div/mul. Signed-off-by: Avi Kivity <avi.kivity@gmail.com> Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-05-21KVM: x86 emulator: add support for writing back the source operandAvi Kivity
Some instructions write back the source operand, not just the destination. Add support for doing this via the decode flags. Gleb: add BUG_ON() to prevent source to be memory operand. Signed-off-by: Avi Kivity <avi.kivity@gmail.com> Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-05-19KVM: get rid of $(addprefix ../../../virt/kvm/, ...) in MakefilesMarc Zyngier
As requested by the KVM maintainers, remove the addprefix used to refer to the main KVM code from the arch code, and replace it with a KVM variable that does the same thing. Tested-by: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Gleb Natapov <gleb@redhat.com> Cc: Christoffer Dall <cdall@cs.columbia.edu> Acked-by: Xiantao Zhang <xiantao.zhang@intel.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Alexander Graf <agraf@suse.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-05-16KVM: MMU: clenaup locking in mmu_free_roots()Gleb Natapov
Do locking around each case separately instead of having one lock and two unlocks. Move root_hpa assignment out of the lock. Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-05-15KVM: x86: limit difference between kvmclock updatesMarcelo Tosatti
kvmclock updates which are isolated to a given vcpu, such as vcpu->cpu migration, should not allow system_timestamp from the rest of the vcpus to remain static. Otherwise ntp frequency correction applies to one vcpu's system_timestamp but not the others. So in those cases, request a kvmclock update for all vcpus. The worst case for a remote vcpu to update its kvmclock is then bounded by maximum nohz sleep latency. Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-05-14KVM: x86: Remove support for reporting coalesced APIC IRQsJan Kiszka
Since the arrival of posted interrupt support we can no longer guarantee that coalesced IRQs are always reported to the IRQ source. Moreover, accumulated APIC timer events could cause a busy loop when a VCPU should rather be halted. The consensus is to remove coalesced tracking from the LAPIC. Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Acked-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-05-12KVM: MMU: Use kvm_mmu_sync_roots() in kvm_mmu_load()Takuya Yoshikawa
No need to open-code this function. Signed-off-by: Takuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp> Reviewed-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-05-11Merge tag 'stable/for-linus-3.10-rc0-tag-two' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen Pull Xen bug-fixes from Konrad Rzeszutek Wilk: - More fixes in the vCPU PVHVM hotplug path. - Add more documentation. - Fix various ARM related issues in the Xen generic drivers. - Updates in the xen-pciback driver per Bjorn's updates. - Mask the x2APIC feature for PV guests. * tag 'stable/for-linus-3.10-rc0-tag-two' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen: xen/pci: Used cached MSI-X capability offset xen/pci: Use PCI_MSIX_TABLE_BIR, not PCI_MSIX_FLAGS_BIRMASK xen: clear IRQ_NOAUTOEN and IRQ_NOREQUEST xen: mask x2APIC feature in PV xen: SWIOTLB is only used on x86 xen/spinlock: Fix check from greater than to be also be greater or equal to. xen/smp/pvhvm: Don't point per_cpu(xen_vpcu, 33 and larger) to shared_info xen/vcpu: Document the xen_vcpu_info and xen_vcpu xen/vcpu/pvhvm: Fix vcpu hotplugging hanging.
2013-05-11Merge branch 'release' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux Pull idle update from Len Brown: "Add support for new Haswell-ULT CPU idle power states" * 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux: intel_idle: initial C8, C9, C10 support tools/power turbostat: display C8, C9, C10 residency
2013-05-10Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal Pull stray syscall bits from Al Viro: "Several syscall-related commits that were missing from the original" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal: switch compat_sys_sysctl to COMPAT_SYSCALL_DEFINE unicore32: just use mmap_pgoff()... unify compat fanotify_mark(2), switch to COMPAT_SYSCALL_DEFINE x86, vm86: fix VM86 syscalls: use SYSCALL_DEFINEx(...)
2013-05-10Merge tag 'kvm-3.10-2' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
Pull kvm fixes from Gleb Natapov: "Most of the fixes are in the emulator since now we emulate more than we did before for correctness sake we see more bugs there, but there is also an OOPS fixed and corruption of xcr0 register." * tag 'kvm-3.10-2' of git://git.kernel.org/pub/scm/virt/kvm/kvm: KVM: emulator: emulate SALC KVM: emulator: emulate XLAT KVM: emulator: emulate AAM KVM: VMX: fix halt emulation while emulating invalid guest sate KVM: Fix kvm_irqfd_init initialization KVM: x86: fix maintenance of guest/host xcr0 state
2013-05-10xen/pci: Used cached MSI-X capability offsetBjorn Helgaas
We now cache the MSI-X capability offset in the struct pci_dev, so no need to find the capability again. Acked-by: Jan Beulich <jbeulich@suse.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> CC: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2013-05-10xen/pci: Use PCI_MSIX_TABLE_BIR, not PCI_MSIX_FLAGS_BIRMASKBjorn Helgaas
PCI_MSIX_FLAGS_BIRMASK is mis-named because the BIR mask is in the Table Offset register, not the flags ("Message Control" per spec) register. Acked-by: Jan Beulich <jbeulich@suse.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> CC: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2013-05-09unify compat fanotify_mark(2), switch to COMPAT_SYSCALL_DEFINEAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-05-09Merge tag 'pci-v3.10-fixes-1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci Pull PCI updates from Bjorn Helgaas: "MSI: PCI: Set ->mask_pos correctly Hotplug: PCI: Delay final fixups until resources are assigned Moorestown: x86/pci/mrst: Use configuration mechanism 1 for 00:00.0, 00:02.0, 00:03.0" * tag 'pci-v3.10-fixes-1' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci: PCI: Delay final fixups until resources are assigned x86/pci/mrst: Use configuration mechanism 1 for 00:00.0, 00:02.0, 00:03.0 PCI: Set ->mask_pos correctly
2013-05-09Merge tag 'gpio-for-linus' of git://git.secretlab.ca/git/linuxLinus Torvalds
Pull removal of GENERIC_GPIO from Grant Likely: "GENERIC_GPIO now synonymous with GPIOLIB. There are no longer any valid cases for enableing GENERIC_GPIO without GPIOLIB, even though it is possible to do so which has been causing confusion and breakage. This branch does the work to completely eliminate GENERIC_GPIO." * tag 'gpio-for-linus' of git://git.secretlab.ca/git/linux: gpio: update gpio Chinese documentation Remove GENERIC_GPIO config option Convert selectors of GENERIC_GPIO to GPIOLIB blackfin: force use of gpiolib m68k: coldfire: use gpiolib mips: pnx833x: remove requirement for GENERIC_GPIO openrisc: default GENERIC_GPIO to false avr32: default GENERIC_GPIO to false xtensa: remove explicit selection of GENERIC_GPIO sh: replace CONFIG_GENERIC_GPIO by CONFIG_GPIOLIB powerpc: remove redundant GENERIC_GPIO selection unicore32: default GENERIC_GPIO to false unicore32: remove unneeded select GENERIC_GPIO arm: plat-orion: use GPIO driver on CONFIG_GPIOLIB arm: remove redundant GENERIC_GPIO selection mips: alchemy: require gpiolib mips: txx9: change GENERIC_GPIO to GPIOLIB mips: loongson: use GPIO driver on CONFIG_GPIOLIB mips: remove redundant GENERIC_GPIO select
2013-05-09KVM: emulator: emulate SALCPaolo Bonzini
This is an almost-undocumented instruction available in 32-bit mode. I say "almost" undocumented because AMD documents it in their opcode maps just to say that it is unavailable in 64-bit mode (sections "A.2.1 One-Byte Opcodes" and "B.3 Invalid and Reassigned Instructions in 64-Bit Mode"). It is roughly equivalent to "sbb %al, %al" except it does not set the flags. Use fastop to emulate it, but do not use the opcode directly because it would fail if the host is 64-bit! Reported-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com> Cc: stable@vger.kernel.org # 3.9 Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-05-09KVM: emulator: emulate XLATPaolo Bonzini
This is used by SGABIOS, KVM breaks with emulate_invalid_guest_state=1. It is just a MOV in disguise, with a funny source address. Reported-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com> Cc: stable@vger.kernel.org # 3.9 Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-05-09KVM: emulator: emulate AAMPaolo Bonzini
This is used by SGABIOS, KVM breaks with emulate_invalid_guest_state=1. AAM needs the source operand to be unsigned; do the same in AAD as well for consistency, even though it does not affect the result. Reported-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com> Cc: stable@vger.kernel.org # 3.9 Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-05-09KVM: VMX: fix halt emulation while emulating invalid guest sateGleb Natapov
The invalid guest state emulation loop does not check halt_request which causes 100% cpu loop while guest is in halt and in invalid state, but more serious issue is that this leaves halt_request set, so random instruction emulated by vm86 #GP exit can be interpreted as halt which causes guest hang. Fix both problems by handling halt_request in emulation loop. Reported-by: Tomas Papan <tomas.papan@gmail.com> Tested-by: Tomas Papan <tomas.papan@gmail.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> CC: stable@vger.kernel.org Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-05-08xen: mask x2APIC feature in PVZhenzhong Duan
On x2apic enabled pvm, doing sysrq+l, got NULL pointer dereference as below. SysRq : Show backtrace of all active CPUs BUG: unable to handle kernel NULL pointer dereference at (null) IP: [<ffffffff8125e3cb>] memcpy+0xb/0x120 Call Trace: [<ffffffff81039633>] ? __x2apic_send_IPI_mask+0x73/0x160 [<ffffffff8103973e>] x2apic_send_IPI_all+0x1e/0x20 [<ffffffff8103498c>] arch_trigger_all_cpu_backtrace+0x6c/0xb0 [<ffffffff81501be4>] ? _raw_spin_lock_irqsave+0x34/0x50 [<ffffffff8131654e>] sysrq_handle_showallcpus+0xe/0x10 [<ffffffff8131616d>] __handle_sysrq+0x7d/0x140 [<ffffffff81316230>] ? __handle_sysrq+0x140/0x140 [<ffffffff81316287>] write_sysrq_trigger+0x57/0x60 [<ffffffff811ca996>] proc_reg_write+0x86/0xc0 [<ffffffff8116dd8e>] vfs_write+0xce/0x190 [<ffffffff8116e3e5>] sys_write+0x55/0x90 [<ffffffff8150a242>] system_call_fastpath+0x16/0x1b That's because apic points to apic_x2apic_cluster or apic_x2apic_phys but the basic element like cpumask isn't initialized. Mask x2APIC feature in pvm to avoid overwrite of apic pointer, update commit message per Konrad's suggestion. Signed-off-by: Zhenzhong Duan <zhenzhong.duan@oracle.com> Tested-by: Tamon Shiose <tamon.shiose@oracle.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2013-05-08xen/spinlock: Fix check from greater than to be also be greater or equal to.Konrad Rzeszutek Wilk
During review of git commit cb9c6f15f318aa3aeb62fe525aa5c6dcf6eee159 ("xen/spinlock: Check against default value of -1 for IRQ line.") Stefano pointed out a bug in the patch. Unfortunatly due to vacation timing the fix was not applied and this patch fixes it up. Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2013-05-08xen/smp/pvhvm: Don't point per_cpu(xen_vpcu, 33 and larger) to shared_infoKonrad Rzeszutek Wilk
As it will point to some data, but not event channel data (the shared_info has an array limited to 32). This means that for PVHVM guests with more than 32 VCPUs without the usage of VCPUOP_register_info any interrupts to VCPUs larger than 32 would have gone unnoticed during early bootup. That is OK, as during early bootup, in smp_init we end up calling the hotplug mechanism (xen_hvm_cpu_notify) which makes the VCPUOP_register_vcpu_info call for all VCPUs and we can receive interrupts on VCPUs 33 and further. This is just a cleanup. Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2013-05-08KVM: x86: fix maintenance of guest/host xcr0 stateMarcelo Tosatti
Emulation of xcr0 writes zero guest_xcr0_loaded variable so that subsequent VM-entry reloads CPU's xcr0 with guests xcr0 value. However, this is incorrect because guest_xcr0_loaded variable is read to decide whether to reload hosts xcr0. In case the vcpu thread is scheduled out after the guest_xcr0_loaded = 0 assignment, and scheduler decides to preload FPU: switch_to { __switch_to __math_state_restore restore_fpu_checking fpu_restore_checking if (use_xsave()) fpu_xrstor_checking xrstor64 with CPU's xcr0 == guests xcr0 Fix by properly restoring hosts xcr0 during emulation of xcr0 writes. Analyzed-by: Ulrich Obergfell <uobergfe@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-05-07Merge branch 'rwsem-optimizations'Linus Torvalds
Merge rwsem optimizations from Michel Lespinasse: "These patches extend Alex Shi's work (which added write lock stealing on the rwsem slow path) in order to provide rwsem write lock stealing on the fast path (that is, without taking the rwsem's wait_lock). I have unfortunately been unable to push this through -next before due to Ingo Molnar / David Howells / Peter Zijlstra being busy with other things. However, this has gotten some attention from Rik van Riel and Davidlohr Bueso who both commented that they felt this was ready for v3.10, and Ingo Molnar has said that he was OK with me pushing directly to you. So, here goes :) Davidlohr got the following test results from pgbench running on a quad-core laptop: | db_size | clients | tps-vanilla | tps-rwsem | +---------+----------+----------------+--------------+ | 160 MB | 1 | 5803 | 6906 | + 19.0% | 160 MB | 2 | 13092 | 15931 | | 160 MB | 4 | 29412 | 33021 | | 160 MB | 8 | 32448 | 34626 | | 160 MB | 16 | 32758 | 33098 | | 160 MB | 20 | 26940 | 31343 | + 16.3% | 160 MB | 30 | 25147 | 28961 | | 160 MB | 40 | 25484 | 26902 | | 160 MB | 50 | 24528 | 25760 | ------------------------------------------------------ | 1.6 GB | 1 | 5733 | 7729 | + 34.8% | 1.6 GB | 2 | 9411 | 19009 | + 101.9% | 1.6 GB | 4 | 31818 | 33185 | | 1.6 GB | 8 | 33700 | 34550 | | 1.6 GB | 16 | 32751 | 33079 | | 1.6 GB | 20 | 30919 | 31494 | | 1.6 GB | 30 | 28540 | 28535 | | 1.6 GB | 40 | 26380 | 27054 | | 1.6 GB | 50 | 25241 | 25591 | ------------------------------------------------------ | 7.6 GB | 1 | 5779 | 6224 | | 7.6 GB | 2 | 10897 | 13611 | + 24.9% | 7.6 GB | 4 | 32683 | 33108 | | 7.6 GB | 8 | 33968 | 34712 | | 7.6 GB | 16 | 32287 | 32895 | | 7.6 GB | 20 | 27770 | 31689 | + 14.1% | 7.6 GB | 30 | 26739 | 29003 | | 7.6 GB | 40 | 24901 | 26683 | | 7.6 GB | 50 | 17115 | 25925 | + 51.5% ------------------------------------------------------ (Davidlohr also has one additional patch which further improves throughput, though I will ask him to send it directly to you as I have suggested some minor changes)." * emailed patches from Michel Lespinasse <walken@google.com>: rwsem: no need for explicit signed longs x86 rwsem: avoid taking slow path when stealing write lock rwsem: do not block readers at head of queue if other readers are active rwsem: implement support for write lock stealing on the fastpath rwsem: simplify __rwsem_do_wake rwsem: skip initial trylock in rwsem_down_write_failed rwsem: avoid taking wait_lock in rwsem_down_write_failed rwsem: use cmpxchg for trying to steal write lock rwsem: more agressive lock stealing in rwsem_down_write_failed rwsem: simplify rwsem_down_write_failed rwsem: simplify rwsem_down_read_failed rwsem: move rwsem_down_failed_common code into rwsem_down_{read,write}_failed rwsem: shorter spinlocked section in rwsem_down_failed_common() rwsem: make the waiter type an enumeration rather than a bitmask
2013-05-07x86 rwsem: avoid taking slow path when stealing write lockMichel Lespinasse
modify __down_write[_nested] and __down_write_trylock to grab the write lock whenever the active count is 0, even if there are queued waiters (they must be writers pending wakeup, since the active count is 0). Note that this is an optimization only; architectures without this optimization will still work fine: - __down_write() would take the slow path which would take the wait_lock and then try stealing the lock (as in the spinlocked rwsem implementation) - __down_write_trylock() would fail, but callers must be ready to deal with that - since there are some writers pending wakeup, they could have raced with us and obtained the lock before we steal it. Signed-off-by: Michel Lespinasse <walken@google.com> Reviewed-by: Peter Hurley <peter@hurleysoftware.com> Acked-by: Davidlohr Bueso <davidlohr.bueso@hp.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-05-07xen/vcpu: Document the xen_vcpu_info and xen_vcpuKonrad Rzeszutek Wilk
They are important structures and it is not clear at first look what they are for. The xen_vcpu is a pointer. By default it points to the shared_info structure (at the CPU offset location). However if the VCPUOP_register_vcpu_info hypercall is implemented we can make the xen_vcpu pointer point to a per-CPU location. Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> [v1: Added comments from Ian Campbell] Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2013-05-06Merge tag 'iommu-updates-v3.10' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu Pull IOMMU updates from Joerg Roedel: "The updates are mostly about the x86 IOMMUs this time. Exceptions are the groundwork for the PAMU IOMMU from Freescale (for a PPC platform) and an extension to the IOMMU group interface. On the x86 side this includes a workaround for VT-d to disable interrupt remapping on broken chipsets. On the AMD-Vi side the most important new feature is a kernel command-line interface to override broken information in IVRS ACPI tables and get interrupt remapping working this way. Besides that there are small fixes all over the place." * tag 'iommu-updates-v3.10' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu: (24 commits) iommu/tegra: Fix printk formats for dma_addr_t iommu: Add a function to find an iommu group by id iommu/vt-d: Remove warning for HPET scope type iommu: Move swap_pci_ref function to drivers/iommu/pci.h. iommu/vt-d: Disable translation if already enabled iommu/amd: fix error return code in early_amd_iommu_init() iommu/AMD: Per-thread IOMMU Interrupt Handling iommu: Include linux/err.h iommu/amd: Workaround for ERBT1312 iommu/amd: Document ivrs_ioapic and ivrs_hpet parameters iommu/amd: Don't report firmware bugs with cmd-line ivrs overrides iommu/amd: Add ioapic and hpet ivrs override iommu/amd: Add early maps for ioapic and hpet iommu/amd: Extend IVRS special device data structure iommu/amd: Move add_special_device() to __init iommu: Fix compile warnings with forward declarations iommu/amd: Properly initialize irq-table lock iommu/amd: Use AMD specific data structure for irq remapping iommu/amd: Remove map_sg_no_iommu() iommu/vt-d: add quirk for broken interrupt remapping on 55XX chipsets ...
2013-05-06xen/vcpu/pvhvm: Fix vcpu hotplugging hanging.Konrad Rzeszutek Wilk
If a user did: echo 0 > /sys/devices/system/cpu/cpu1/online echo 1 > /sys/devices/system/cpu/cpu1/online we would (this a build with DEBUG enabled) get to: smpboot: ++++++++++++++++++++=_---CPU UP 1 .. snip.. smpboot: Stack at about ffff880074c0ff44 smpboot: CPU1: has booted. and hang. The RCU mechanism would kick in an try to IPI the CPU1 but the IPIs (and all other interrupts) would never arrive at the CPU1. At first glance at least. A bit digging in the hypervisor trace shows that (using xenanalyze): [vla] d4v1 vec 243 injecting 0.043163027 --|x d4v1 intr_window vec 243 src 5(vector) intr f3 ] 0.043163639 --|x d4v1 vmentry cycles 1468 ] 0.043164913 --|x d4v1 vmexit exit_reason PENDING_INTERRUPT eip ffffffff81673254 0.043164913 --|x d4v1 inj_virq vec 243 real [vla] d4v1 vec 243 injecting 0.043164913 --|x d4v1 intr_window vec 243 src 5(vector) intr f3 ] 0.043165526 --|x d4v1 vmentry cycles 1472 ] 0.043166800 --|x d4v1 vmexit exit_reason PENDING_INTERRUPT eip ffffffff81673254 0.043166800 --|x d4v1 inj_virq vec 243 real [vla] d4v1 vec 243 injecting there is a pending event (subsequent debugging shows it is the IPI from the VCPU0 when smpboot.c on VCPU1 has done "set_cpu_online(smp_processor_id(), true)") and the guest VCPU1 is interrupted with the callback IPI (0xf3 aka 243) which ends up calling __xen_evtchn_do_upcall. The __xen_evtchn_do_upcall seems to do *something* but not acknowledge the pending events. And the moment the guest does a 'cli' (that is the ffffffff81673254 in the log above) the hypervisor is invoked again to inject the IPI (0xf3) to tell the guest it has pending interrupts. This repeats itself forever. The culprit was the per_cpu(xen_vcpu, cpu) pointer. At the bootup we set each per_cpu(xen_vcpu, cpu) to point to the shared_info->vcpu_info[vcpu] but later on use the VCPUOP_register_vcpu_info to register per-CPU structures (xen_vcpu_setup). This is used to allow events for more than 32 VCPUs and for performance optimizations reasons. When the user performs the VCPU hotplug we end up calling the the xen_vcpu_setup once more. We make the hypercall which returns -EINVAL as it does not allow multiple registration calls (and already has re-assigned where the events are being set). We pick the fallback case and set per_cpu(xen_vcpu, cpu) to point to the shared_info->vcpu_info[vcpu] (which is a good fallback during bootup). However the hypervisor is still setting events in the register per-cpu structure (per_cpu(xen_vcpu_info, cpu)). As such when the events are set by the hypervisor (such as timer one), and when we iterate in __xen_evtchn_do_upcall we end up reading stale events from the shared_info->vcpu_info[vcpu] instead of the per_cpu(xen_vcpu_info, cpu) structures. Hence we never acknowledge the events that the hypervisor has set and the hypervisor keeps on reminding us to ack the events which we never do. The fix is simple. Don't on the second time when xen_vcpu_setup is called over-write the per_cpu(xen_vcpu, cpu) if it points to per_cpu(xen_vcpu_info). Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> CC: stable@vger.kernel.org Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2013-05-05Merge tag 'kvm-3.10-1' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
Pull kvm updates from Gleb Natapov: "Highlights of the updates are: general: - new emulated device API - legacy device assignment is now optional - irqfd interface is more generic and can be shared between arches x86: - VMCS shadow support and other nested VMX improvements - APIC virtualization and Posted Interrupt hardware support - Optimize mmio spte zapping ppc: - BookE: in-kernel MPIC emulation with irqfd support - Book3S: in-kernel XICS emulation (incomplete) - Book3S: HV: migration fixes - BookE: more debug support preparation - BookE: e6500 support ARM: - reworking of Hyp idmaps s390: - ioeventfd for virtio-ccw And many other bug fixes, cleanups and improvements" * tag 'kvm-3.10-1' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (204 commits) kvm: Add compat_ioctl for device control API KVM: x86: Account for failing enable_irq_window for NMI window request KVM: PPC: Book3S: Add API for in-kernel XICS emulation kvm/ppc/mpic: fix missing unlock in set_base_addr() kvm/ppc: Hold srcu lock when calling kvm_io_bus_read/write kvm/ppc/mpic: remove users kvm/ppc/mpic: fix mmio region lists when multiple guests used kvm/ppc/mpic: remove default routes from documentation kvm: KVM_CAP_IOMMU only available with device assignment ARM: KVM: iterate over all CPUs for CPU compatibility check KVM: ARM: Fix spelling in error message ARM: KVM: define KVM_ARM_MAX_VCPUS unconditionally KVM: ARM: Fix API documentation for ONE_REG encoding ARM: KVM: promote vfp_host pointer to generic host cpu context ARM: KVM: add architecture specific hook for capabilities ARM: KVM: perform HYP initilization for hotplugged CPUs ARM: KVM: switch to a dual-step HYP init code ARM: KVM: rework HYP page table freeing ARM: KVM: enforce maximum size for identity mapped code ARM: KVM: move to a KVM provided HYP idmap ...
2013-05-05Merge branch 'perf-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf fixes from Ingo Molnar: "Misc fixes plus a small hw-enablement patch for Intel IB model 58 uncore events" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf/x86/intel/lbr: Demand proper privileges for PERF_SAMPLE_BRANCH_KERNEL perf/x86/intel/lbr: Fix LBR filter perf/x86: Blacklist all MEM_*_RETIRED events for Ivy Bridge perf: Fix vmalloc ring buffer pages handling perf/x86/intel: Fix unintended variable name reuse perf/x86/intel: Add support for IvyBridge model 58 Uncore perf/x86/intel: Fix typo in perf_event_intel_uncore.c x86: Eliminate irq_mis_count counted in arch_irq_stat
2013-05-05perf/x86/intel/lbr: Demand proper privileges for PERF_SAMPLE_BRANCH_KERNELPeter Zijlstra
We should always have proper privileges when requesting kernel data. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: <stable@kernel.org> Cc: Andi Kleen <ak@linux.intel.com> Cc: eranian@google.com Link: http://lkml.kernel.org/r/20130503121256.230745028@chello.nl [ Fix build error reported by fengguang.wu@intel.com, propagate error code back. ] Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: http://lkml.kernel.org/n/tip-v0x9ky3ahzr6nm3c6ilwrili@git.kernel.org