- 27 Jun, 2013 14 commits
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Yoshihiro YUNOMAE authored
Add a tracepoint write_tsc_offset for tracing TSC offset change. We want to merge ftrace's trace data of guest OSs and the host OS using TSC for timestamp in chronological order. We need "TSC offset" values for each guest when merge those because the TSC value on a guest is always the host TSC plus guest's TSC offset. If we get the TSC offset values, we can calculate the host TSC value for each guest events from the TSC offset and the event TSC value. The host TSC values of the guest events are used when we want to merge trace data of guests and the host in chronological order. (Note: the trace_clock of both the host and the guest must be set x86-tsc in this case) This tracepoint also records vcpu_id which can be used to merge trace data for SMP guests. A merge tool will read TSC offset for each vcpu, then the tool converts guest TSC values to host TSC values for each vcpu. TSC offset is stored in the VMCS by vmx_write_tsc_offset() or vmx_adjust_tsc_offset(). KVM executes the former function when a guest boots. The latter function is executed when kvm clock is updated. Only host can read TSC offset value from VMCS, so a host needs to output TSC offset value when TSC offset is changed. Since the TSC offset is not often changed, it could be overwritten by other frequent events while tracing. To avoid that, I recommend to use a special instance for getting this event: 1. set a instance before booting a guest # cd /sys/kernel/debug/tracing/instances # mkdir tsc_offset # cd tsc_offset # echo x86-tsc > trace_clock # echo 1 > events/kvm/kvm_write_tsc_offset/enable 2. boot a guest Signed-off-by:
Yoshihiro YUNOMAE <yoshihiro.yunomae.ez@hitachi.com> Cc: Joerg Roedel <joro@8bytes.org> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Gleb Natapov <gleb@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Acked-by:
Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by:
Gleb Natapov <gleb@redhat.com>
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Takuya Yoshikawa authored
Without this information, users will just see unexpected performance problems and there is little chance we will get good reports from them: note that mmio generation is increased even when we just start, or stop, dirty logging for some memory slot, in which case users cannot expect all shadow pages to be zapped. printk_ratelimited() is used for this taking into account the problems that we can see the information many times when we start multiple VMs and guests can trigger this by reading ROM in a loop for example. Signed-off-by:
Takuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp> Signed-off-by:
Paolo Bonzini <pbonzini@redhat.com>
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Xiao Guangrong authored
Document it to Documentation/virtual/kvm/mmu.txt Signed-off-by:
Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> Signed-off-by:
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Xiao Guangrong authored
Document it to Documentation/virtual/kvm/mmu.txt Signed-off-by:
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Xiao Guangrong authored
Document fast page fault to Documentation/virtual/kvm/mmu.txt Signed-off-by:
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Xiao Guangrong authored
Document it to Documentation/virtual/kvm/mmu.txt Signed-off-by:
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Xiao Guangrong authored
Document write_flooding_count to Documentation/virtual/kvm/mmu.txt Signed-off-by:
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Xiao Guangrong authored
Document it to Documentation/virtual/kvm/mmu.txt Signed-off-by:
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Xiao Guangrong authored
Drop kvm_mmu_zap_mmio_sptes and use kvm_mmu_invalidate_zap_all_pages instead to handle mmio generation number overflow Signed-off-by:
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Xiao Guangrong authored
Then it has the chance to trigger mmio generation number wrap-around Signed-off-by:
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Xiao Guangrong authored
It is useful for debug mmio spte invalidation Signed-off-by:
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Xiao Guangrong authored
This patch tries to introduce a very simple and scale way to invalidate all mmio sptes - it need not walk any shadow pages and hold mmu-lock KVM maintains a global mmio valid generation-number which is stored in kvm->memslots.generation and every mmio spte stores the current global generation-number into his available bits when it is created When KVM need zap all mmio sptes, it just simply increase the global generation-number. When guests do mmio access, KVM intercepts a MMIO #PF then it walks the shadow page table and get the mmio spte. If the generation-number on the spte does not equal the global generation-number, it will go to the normal #PF handler to update the mmio spte Since 19 bits are used to store generation-number on mmio spte, we zap all mmio sptes when the number is round Signed-off-by:
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Xiao Guangrong authored
Define some meaningful names instead of raw code Signed-off-by:
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Xiao Guangrong authored
Store the generation-number into bit3 ~ bit11 and bit52 ~ bit61, totally 19 bits can be used, it should be enough for nearly all most common cases In this patch, the generation-number is always 0, it will be changed in the later patch [Gleb: masking generation bits from spte in get_mmio_spte_gfn() and get_mmio_spte_access()] Signed-off-by:
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- 20 Jun, 2013 8 commits
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Xiao Guangrong authored
Let mmio spte only use bit62 and bit63 on upper 32 bits, then bit 52 ~ bit 61 can be used for other purposes Signed-off-by:
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Thomas Huth authored
Added some missing validity checks for the operands and fixed the priority of exceptions for some function codes according to the "Principles of Operation" document. Signed-off-by:
Thomas Huth <thuth@linux.vnet.ibm.com> Acked-by:
Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by:
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Thomas Huth authored
LCTL and LCTLG are also privileged instructions, thus there is no need for treating them separately from the other instructions in priv.c. So this patch moves these two instructions to priv.c, adds a check for supervisor state and simplifies the "handle_eb" instruction decoding by merging the two eb_handlers jump tables from intercept.c and priv.c into one table only. Signed-off-by:
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Thomas Huth authored
When a guest calls the TPI instruction, the second operand address could point to an invalid location. In this case the problem should be signaled to the guest by throwing an access exception. Signed-off-by:
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Thomas Huth authored
DIAGNOSE is a privileged instruction and thus we must make sure that we are in supervisor mode before taking any other actions. Signed-off-by:
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Thomas Huth authored
We need more fine-grained control about the point in time when we check for privileged instructions, since the exceptions that can happen during an instruction have a well-defined priority. For example, for the PFMF instruction, the check for PGM_PRIVILEGED_OP must happen after the check for PGM_OPERATION since the latter has a higher precedence - thus the check for privileged operation must not be done in kvm_s390_handle_b9() already. Signed-off-by:
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Thomas Huth authored
TPROT is a privileged instruction and thus should generate a privileged operation exception when the problem state bit is not cleared in the PSW. Signed-off-by:
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Thomas Huth authored
Renamed the PGM_PRIVILEGED_OPERATION define to PGM_PRIVILEGED_OP since this define was way longer than the other PGM_* defines and caused the code often to exceed the 80 columns limit when not split to multiple lines. Signed-off-by:
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- 19 Jun, 2013 2 commits
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Xiao Guangrong authored
Update the document to match the current reverse mapping of parent_pte Signed-off-by:
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Alexey Kardashevskiy authored
Signed-off-by:
Alexey Kardashevskiy <aik@ozlabs.ru> Signed-off-by:
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- 17 Jun, 2013 6 commits
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Thomas Huth authored
The handle_epsw() function calculated the first register in the wrong way, so that it always used r0 by mistake. Now the code uses the common helper function for decoding the registers of rre functions instead to avoid such mistakes. Signed-off-by:
Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by:
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Heinz Graalfs authored
This patch is based on an original patch of David Hildenbrand. The perf core implementation calls architecture specific code in order to ask for specific information for a particular sample: perf_instruction_pointer() When perf core code asks for the instruction pointer, architecture specific code must detect if a KVM guest was running when the sample was taken. A sample can be associated with a KVM guest when the PSW supervisor state bit is set and the PSW instruction pointer part contains the address of 'sie_exit'. A KVM guest's instruction pointer information is then retrieved via gpsw entry pointed to by the sie control-block. perf_misc_flags() perf code code calls this function in order to associate the kernel vs. user state infomation with a particular sample. Architecture specific code must also first detectif a KVM guest was running at the time the sample was taken. Signed-off-by:
Heinz Graalfs <graalfs@linux.vnet.ibm.com> Reviewed-by:
Hendrik Brueckner <brueckner@linux.vnet.ibm.com> Signed-off-by:
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Christian Borntraeger authored
Lets use the common waitqueue for kvm cpus on s390. By itself it is just a cleanup, but it should also improve the accuracy of diag 0x44 which is implemented via kvm_vcpu_on_spin. kvm_vcpu_on_spin has an explicit check for waiting on the waitqueue to optimize the yielding. Signed-off-by:
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Michael Mueller authored
cleanup of arch specific code to use common code provided vcpu slab cache instead of kzalloc() provided memory Signed-off-by:
Michael Mueller <mimu@linux.vnet.ibm.com> Signed-off-by:
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Christian Borntraeger authored
This patch enables kvm to give large pages to the guest. The heavy lifting is done by the hardware, the host only has to take care of the PFMF instruction, which is also part of EDAT-1. We also support the non-quiescing key setting facility if the host supports it, to behave similar to the interpretation of sske. Signed-off-by:
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Christian Borntraeger authored
From time to time we need to set the guest storage key. Lets provide a helper function that handles the changes with all the right locking and checking. Signed-off-by:
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- 12 Jun, 2013 1 commit
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Marcelo Tosatti authored
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=969644Signed-off-by:
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- 05 Jun, 2013 9 commits
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Gleb Natapov authored
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:
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Xiao Guangrong authored
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:
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Xiao Guangrong authored
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:
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Xiao Guangrong authored
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:
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Xiao Guangrong authored
The obsolete page will be zapped soon, do not reuse it to reduce future page fault Signed-off-by:
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Xiao Guangrong authored
It is good for debug and development Signed-off-by:
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Xiao Guangrong authored
Show sp->mmu_valid_gen Signed-off-by:
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Xiao Guangrong authored
Replace kvm_mmu_zap_all by kvm_mmu_invalidate_zap_all_pages Signed-off-by:
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Xiao Guangrong authored
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:
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