- 03 Dec, 2009 40 commits
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Carsten Otte authored
This patch corrects the checking of the new address for the prefix register. On s390, the prefix register is used to address the cpu's lowcore (address 0...8k). This check is supposed to verify that the memory is readable and present. copy_from_guest is a helper function, that can be used to read from guest memory. It applies prefixing, adds the start address of the guest memory in user, and then calls copy_from_user. Previous code was obviously broken for two reasons: - prefixing should not be applied here. The current prefix register is going to be updated soon, and the address we're looking for will be 0..8k after we've updated the register - we're adding the guest origin (gmsor) twice: once in subject code and once in copy_from_guest With kuli, we did not hit this problem because (a) we were lucky with previous prefix register content, and (b) our guest memory was mmaped very low into user address space. Cc: stable@kernel.org Signed-off-by:
Carsten Otte <cotte@de.ibm.com> Reported-by:
Alexander Graf <agraf@suse.de> Signed-off-by:
Avi Kivity <avi@redhat.com>
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Avi Kivity authored
This way, we don't leave a dangling notifier on cpu hotunplug or module unload. In particular, module unload leaves the notifier pointing into freed memory. Signed-off-by:
Marcelo Tosatti <mtosatti@redhat.com>
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Sheng Yang authored
Otherwise would cause VMEntry failure when using ept=0 on unrestricted guest supported processors. Signed-off-by:
Sheng Yang <sheng@linux.intel.com> Signed-off-by:
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Avi Kivity authored
While we are never normally passed an instruction that exceeds 15 bytes, smp games can cause us to attempt to interpret one, which will cause large latencies in non-preempt hosts. Cc: stable@kernel.org Signed-off-by: -
Carsten Otte authored
This patch moves s390 processor status word into the base kvm_run struct and keeps it up-to date on all userspace exits. The userspace ABI is broken by this, however there are no applications in the wild using this. A capability check is provided so users can verify the updated API exists. Cc: stable@kernel.org Signed-off-by:
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Jan Kiszka authored
This new IOCTL exports all yet user-invisible states related to exceptions, interrupts, and NMIs. Together with appropriate user space changes, this fixes sporadic problems of vmsave/restore, live migration and system reset. [avi: future-proof abi by adding a flags field] Signed-off-by:
Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by:
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Avi Kivity authored
These happen when we trap an exception when another exception is being delivered; we only expect these with MCEs and page faults. If something unexpected happens, things probably went south and we're better off reporting an internal error and freezing. Signed-off-by: -
Avi Kivity authored
Usually userspace will freeze the guest so we can inspect it, but some internal state is not available. Add extra data to internal error reporting so we can expose it to the debugger. Extra data is specific to the suberror. Signed-off-by: -
Jan Kiszka authored
Obviously, people tend to extend this header at the bottom - more or less blindly. Ensure that deprecated stuff gets its own corner again by moving things to the top. Also add some comments and reindent IOCTLs to make them more readable and reduce the risk of number collisions. Signed-off-by:
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Jan Kiszka authored
Decouple KVM_GUESTDBG_INJECT_DB and KVM_GUESTDBG_INJECT_BP from KVM_GUESTDBG_ENABLE, their are actually orthogonal. At this chance, avoid triggering the WARN_ON in kvm_queue_exception if there is already an exception pending and reject such invalid requests. Signed-off-by:
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Marcelo Tosatti authored
Otherwise kvm might attempt to dereference a NULL pointer. Signed-off-by:
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Marcelo Tosatti authored
Otherwise kvm might attempt to dereference a NULL pointer. Signed-off-by:
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Marcelo Tosatti authored
Otherwise kvm will leak memory on multiple KVM_CREATE_IRQCHIP. Also serialize multiple accesses with kvm->lock. Signed-off-by:
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Avi Kivity authored
This variable is used to communicate between a caller and a callee; switch to a function argument instead. Signed-off-by: -
Marcelo Tosatti authored
Large page translations are always synchronized (either in level 3 or level 2), so its not necessary to properly deal with them in the invlpg handler. Signed-off-by:
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Marcelo Tosatti authored
GUEST_CR3 is updated via kvm_set_cr3 whenever CR3 is modified from outside guest context. Similarly pdptrs are updated via load_pdptrs. Let kvm_set_cr3 perform the update, removing it from the vcpu_run fast path. Signed-off-by:
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Gleb Natapov authored
Probably introduced by a bad merge. Signed-off-by:
Gleb Natapov <gleb@redhat.com> Signed-off-by:
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Hollis Blanchard authored
The old BUILD_BUG_ON implementation didn't work with __builtin_constant_p(). Fixing that revealed this test had been inverted for a long time without anybody noticing... Signed-off-by:
Hollis Blanchard <hollisb@us.ibm.com> Signed-off-by:
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Avi Kivity authored
Instead of reloading syscall MSRs on every preemption, use the new shared msr infrastructure to reload them at the last possible minute (just before exit to userspace). Improves vcpu/idle/vcpu switches by about 2000 cycles (when EFER needs to be reloaded as well). [jan: fix slot index missing indirection] Signed-off-by:
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Avi Kivity authored
The various syscall-related MSRs are fairly expensive to switch. Currently we switch them on every vcpu preemption, which is far too often: - if we're switching to a kernel thread (idle task, threaded interrupt, kernel-mode virtio server (vhost-net), for example) and back, then there's no need to switch those MSRs since kernel threasd won't be exiting to userspace. - if we're switching to another guest running an identical OS, most likely those MSRs will have the same value, so there's little point in reloading them. - if we're running the same OS on the guest and host, the MSRs will have identical values and reloading is unnecessary. This patch uses the new user return notifiers to implement last-minute switching, and checks the msr values to avoid unnecessary reloading. Signed-off-by: -
Avi Kivity authored
Currently MSR_KERNEL_GS_BASE is saved and restored as part of the guest/host msr reloading. Since we wish to lazy-restore all the other msrs, save and reload MSR_KERNEL_GS_BASE explicitly instead of using the common code. Signed-off-by: -
Eduardo Habkost authored
The svm_set_cr0() call will initialize save->cr0 properly even when npt is enabled, clearing the NW and CD bits as expected, so we don't need to initialize it manually for npt_enabled anymore. Signed-off-by:
Eduardo Habkost <ehabkost@redhat.com> Signed-off-by:
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Eduardo Habkost authored
svm_vcpu_reset() was not properly resetting the contents of the guest-visible cr0 register, causing the following issue: https://bugzilla.redhat.com/show_bug.cgi?id=525699 Without resetting cr0 properly, the vcpu was running the SIPI bootstrap routine with paging enabled, making the vcpu get a pagefault exception while trying to run it. Instead of setting vmcb->save.cr0 directly, the new code just resets kvm->arch.cr0 and calls kvm_set_cr0(). The bits that were set/cleared on vmcb->save.cr0 (PG, WP, !CD, !NW) will be set properly by svm_set_cr0(). kvm_set_cr0() is used instead of calling svm_set_cr0() directly to make sure kvm_mmu_reset_context() is called to reset the mmu to nonpaging mode. Signed-off-by:
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Eduardo Habkost authored
This should have no effect, it is just to make the code clearer. Signed-off-by:
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Arnd Bergmann authored
With big endian userspace, we can't quite figure out if a pointer is 32 bit (shifted >> 32) or 64 bit when we read a 64 bit pointer. This is what happens with dirty logging. To get the pointer interpreted correctly, we thus need Arnd's patch to implement a compat layer for the ioctl: A better way to do this is to add a separate compat_ioctl() method that converts this for you. Based on initial patch from Arnd Bergmann. Signed-off-by:
Arnd Bergmann <arnd@arndb.de> Signed-off-by:
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Glauber Costa authored
When we migrate a kvm guest that uses pvclock between two hosts, we may suffer a large skew. This is because there can be significant differences between the monotonic clock of the hosts involved. When a new host with a much larger monotonic time starts running the guest, the view of time will be significantly impacted. Situation is much worse when we do the opposite, and migrate to a host with a smaller monotonic clock. This proposed ioctl will allow userspace to inform us what is the monotonic clock value in the source host, so we can keep the time skew short, and more importantly, never goes backwards. Userspace may also need to trigger the current data, since from the first migration onwards, it won't be reflected by a simple call to clock_gettime() anymore. [marcelo: future-proof abi with a flags field] [jan: fix KVM_GET_CLOCK by clearing flags field instead of checking it] Signed-off-by:
Glauber Costa <glommer@redhat.com> Signed-off-by:
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Marcelo Tosatti authored
find_first_zero_bit works with bit numbers, not bytes. Fixes https://sourceforge.net/tracker/?func=detail&aid=2847560&group_id=180599&atid=893831Reported-by:
"Xu, Jiajun" <jiajun.xu@intel.com> Cc: stable@kernel.org Signed-off-by:
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Jan Kiszka authored
Push the NMI-related singlestep variable into vcpu_svm. It's dealing with an AMD-specific deficit, nothing generic for x86. Acked-by:
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Jan Kiszka authored
Commit 705c5323 opened the doors of hell by unconditionally injecting single-step flags as long as guest_debug signaled this. This doesn't work when the guest branches into some interrupt or exception handler and triggers a vmexit with flag reloading. Fix it by saving cs:rip when user space requests single-stepping and restricting the trace flag injection to this guest code position. Signed-off-by:
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Ed Swierk authored
Support for Xen PV-on-HVM guests can be implemented almost entirely in userspace, except for handling one annoying MSR that maps a Xen hypercall blob into guest address space. A generic mechanism to delegate MSR writes to userspace seems overkill and risks encouraging similar MSR abuse in the future. Thus this patch adds special support for the Xen HVM MSR. I implemented a new ioctl, KVM_XEN_HVM_CONFIG, that lets userspace tell KVM which MSR the guest will write to, as well as the starting address and size of the hypercall blobs (one each for 32-bit and 64-bit) that userspace has loaded from files. When the guest writes to the MSR, KVM copies one page of the blob from userspace to the guest. I've tested this patch with a hacked-up version of Gerd's userspace code, booting a number of guests (CentOS 5.3 i386 and x86_64, and FreeBSD 8.0-RC1 amd64) and exercising PV network and block devices. [jan: fix i386 build warning] [avi: future proof abi with a flags field] Signed-off-by:
Ed Swierk <eswierk@aristanetworks.com> Signed-off-by:
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Jan Kiszka authored
This (broken) check dates back to the days when this code was shared across architectures. x86 has IOMEM, so drop it. Signed-off-by:
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Marcelo Tosatti authored
There's no kvm_run argument anymore. Signed-off-by: -
Zachary Amsden authored
If cpufreq can't determine the CPU khz, or cpufreq is not compiled in, we should fallback to the measured TSC khz. Signed-off-by:
Zachary Amsden <zamsden@redhat.com> Signed-off-by:
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Mark Langsdorf authored
New AMD processors (Family 0x10 models 8+) support the Pause Filter Feature. This feature creates a new field in the VMCB called Pause Filter Count. If Pause Filter Count is greater than 0 and intercepting PAUSEs is enabled, the processor will increment an internal counter when a PAUSE instruction occurs instead of intercepting. When the internal counter reaches the Pause Filter Count value, a PAUSE intercept will occur. This feature can be used to detect contended spinlocks, especially when the lock holding VCPU is not scheduled. Rescheduling another VCPU prevents the VCPU seeking the lock from wasting its quantum by spinning idly. Experimental results show that most spinlocks are held for less than 1000 PAUSE cycles or more than a few thousand. Default the Pause Filter Counter to 3000 to detect the contended spinlocks. Processor support for this feature is indicated by a CPUID bit. On a 24 core system running 4 guests each with 16 VCPUs, this patch improved overall performance of each guest's 32 job kernbench by approximately 3-5% when combined with a scheduler algorithm thati caused the VCPU to sleep for a brief period. Further performance improvement may be possible with a more sophisticated yield algorithm. Signed-off-by:
Mark Langsdorf <mark.langsdorf@amd.com> Signed-off-by:
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Zhai, Edwin authored
New NHM processors will support Pause-Loop Exiting by adding 2 VM-execution control fields: PLE_Gap - upper bound on the amount of time between two successive executions of PAUSE in a loop. PLE_Window - upper bound on the amount of time a guest is allowed to execute in a PAUSE loop If the time, between this execution of PAUSE and previous one, exceeds the PLE_Gap, processor consider this PAUSE belongs to a new loop. Otherwise, processor determins the the total execution time of this loop(since 1st PAUSE in this loop), and triggers a VM exit if total time exceeds the PLE_Window. * Refer SDM volume 3b section 21.6.13 & 22.1.3. Pause-Loop Exiting can be used to detect Lock-Holder Preemption, where one VP is sched-out after hold a spinlock, then other VPs for same lock are sched-in to waste the CPU time. Our tests indicate that most spinlocks are held for less than 212 cycles. Performance tests show that with 2X LP over-commitment we can get +2% perf improvement for kernel build(Even more perf gain with more LPs). Signed-off-by:Zhai Edwin <edwin.zhai@intel.com> Signed-off-by:
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Zhai, Edwin authored
Introduce kvm_vcpu_on_spin, to be used by VMX/SVM to yield processing once the cpu detects pause-based looping. Signed-off-by:
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Joerg Roedel authored
With all important informations now delivered through tracepoints we can savely remove the nsvm_printk debugging code for nested svm. Signed-off-by:
Joerg Roedel <joerg.roedel@amd.com> Signed-off-by:
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Joerg Roedel authored
This patch adds a tracepoint for the event that the guest executed the SKINIT instruction. This information is important because SKINIT is an SVM extenstion not yet implemented by nested SVM and we may need this information for debugging hypervisors that do not yet run on nested SVM. Signed-off-by:
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Joerg Roedel authored
This patch adds a tracepoint for the event that the guest executed the INVLPGA instruction. Signed-off-by:
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Joerg Roedel authored
This patch adds a special tracepoint for the event that a nested #vmexit is injected because kvm wants to inject an interrupt into the guest. Signed-off-by:
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