- 03 Dec, 2009 40 commits
-
-
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:
Marcelo Tosatti <mtosatti@redhat.com>
-
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:
-
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:
-
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:
-
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:
-
Joerg Roedel authored
This patch adds a tracepoint for the event that the guest executed the INVLPGA instruction. Signed-off-by:
-
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:
-
Joerg Roedel authored
This patch adds a tracepoint for a nested #vmexit that gets re-injected to the guest. Signed-off-by:
-
Joerg Roedel authored
This patch adds a tracepoint for every #vmexit we get from a nested guest. Signed-off-by:
-
Joerg Roedel authored
This patch adds a dedicated kvm tracepoint for a nested vmrun. Signed-off-by:
-
Joerg Roedel authored
The nested SVM code emulates a #vmexit caused by a request to open the irq window right in the request function. This is a bug because the request function runs with preemption and interrupts disabled but the #vmexit emulation might sleep. This can cause a schedule()-while-atomic bug and is fixed with this patch. Signed-off-by:
-
Alexander Graf authored
If event_inj is valid on a #vmexit the host CPU would write the contents to exit_int_info, so the hypervisor knows that the event wasn't injected. We don't do this in nested SVM by now which is a bug and fixed by this patch. Signed-off-by:
Alexander Graf <agraf@suse.de> Signed-off-by:
-
Glauber Costa authored
For a while now, we are issuing a rdmsr instruction to find out which msrs in our save list are really supported by the underlying machine. However, it fails to account for kvm-specific msrs, such as the pvclock ones. This patch moves then to the beginning of the list, and skip testing them. Cc: stable@kernel.org Signed-off-by:
Glauber Costa <glommer@redhat.com> Signed-off-by:
-
Jan Kiszka authored
Push TF and RF injection and filtering on guest single-stepping into the vender get/set_rflags callbacks. This makes the whole mechanism more robust wrt user space IOCTL order and instruction emulations. Signed-off-by:
Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by:
Avi Kivity <avi@redhat.com>
-
Marcelo Tosatti authored
Disable paravirt MMU capability reporting, so that new (or rebooted) guests switch to native operation. Paravirt MMU is a burden to maintain and does not bring significant advantages compared to shadow anymore. Signed-off-by:
-
Jan Kiszka authored
Much of so far vendor-specific code for setting up guest debug can actually be handled by the generic code. This also fixes a minor deficit in the SVM part /wrt processing KVM_GUESTDBG_ENABLE. Signed-off-by:
-
Juan Quintela authored
Now, also remove pre_task_link setting in save_state_to_tss16. commit b237ac37 Author: Gleb Natapov <gleb@redhat.com> Date: Mon Mar 30 16:03:24 2009 +0300 KVM: Fix task switch back link handling. CC: Gleb Natapov <gleb@redhat.com> Signed-off-by:
Juan Quintela <quintela@redhat.com> Signed-off-by:
-
Zachary Amsden authored
Both VMX and SVM require per-cpu memory allocation, which is done at module init time, for only online cpus. Backend was not allocating enough structure for all possible CPUs, so new CPUs coming online could not be hardware enabled. Signed-off-by:
Zachary Amsden <zamsden@redhat.com> Signed-off-by:
-
Zachary Amsden authored
Signed-off-by:
-
Zachary Amsden authored
They are globals, not clearly protected by any ordering or locking, and vulnerable to various startup races. Instead, for variable TSC machines, register the cpufreq notifier and get the TSC frequency directly from the cpufreq machinery. Not only is it always right, it is also perfectly accurate, as no error prone measurement is required. On such machines, when a new CPU online is brought online, it isn't clear what frequency it will start with, and it may not correspond to the reference, thus in hardware_enable we clear the cpu_tsc_khz variable to zero and make sure it is set before running on a VCPU. Signed-off-by:
-
Zachary Amsden authored
Signed-off-by:
-
Jiri Slaby authored
Stanse found 2 lock imbalances in kvm_request_irq_source_id and kvm_free_irq_source_id. They omit to unlock kvm->irq_lock on fail paths. Fix that by adding unlock labels at the end of the functions and jump there from the fail paths. Signed-off-by:
Jiri Slaby <jirislaby@gmail.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by:
-
Joerg Roedel authored
This patch replaces them with native_read_tsc() which can also be used in expressions and saves a variable on the stack in this case. Signed-off-by:
-
Joerg Roedel authored
The exit_int_info field is only written by the hardware and never read. So it does not need to be copied on a vmrun emulation. Signed-off-by:
-
Joerg Roedel authored
This patch reorganizes the logic in svm_interrupt_allowed to make it better to read. This is important because the logic is a lot more complicated with Nested SVM. Signed-off-by:
-
Huang Weiyi authored
Remove duplicated #include('s) in arch/x86/kvm/lapic.c Signed-off-by:Huang Weiyi <weiyi.huang@gmail.com> Signed-off-by:
-
Alexander Graf authored
X86 CPUs need to have some magic happening to enable the virtualization extensions on them. This magic can result in unpleasant results for users, like blocking other VMMs from working (vmx) or using invalid TLB entries (svm). Currently KVM activates virtualization when the respective kernel module is loaded. This blocks us from autoloading KVM modules without breaking other VMMs. To circumvent this problem at least a bit, this patch introduces on demand activation of virtualization. This means, that instead virtualization is enabled on creation of the first virtual machine and disabled on destruction of the last one. So using this, KVM can be easily autoloaded, while keeping other hypervisors usable. Signed-off-by:
-
Marcelo Tosatti authored
nested_svm_map unnecessarily takes mmap_sem around gfn_to_page, since gfn_to_page / get_user_pages are responsible for it. Signed-off-by:
-
Mohammed Gamal authored
- Change returned handle_invalid_guest_state() to return relevant exit codes - Move triggering the emulation from vmx_vcpu_run() to vmx_handle_exit() - Return to userspace instead of repeatedly trying to emulate instructions that have already failed Signed-off-by:
Mohammed Gamal <m.gamal005@gmail.com> Signed-off-by:
-
Mohammed Gamal authored
This adds pusha and popa instructions (opcodes 0x60-0x61), this enables booting MINIX with invalid guest state emulation on. [marcelo: remove unused variable] Signed-off-by:
-
Mohammed Gamal authored
Add missing decoder flags for or instructions (0xc-0xd). Signed-off-by:
-
Avi Kivity authored
Signed-off-by: -
Avi Kivity authored
Not the incorrect -EINVAL. Signed-off-by: -
Gleb Natapov authored
The only thing it protects now is interrupt injection into lapic and this can work lockless. Even now with kvm->irq_lock in place access to lapic is not entirely serialized since vcpu access doesn't take kvm->irq_lock. Signed-off-by:
Gleb Natapov <gleb@redhat.com> Signed-off-by:
-
Gleb Natapov authored
The allows removal of irq_lock from the injection path. Signed-off-by:
-
Gleb Natapov authored
Use RCU locking for mask/ack notifiers lists. Signed-off-by:
-
Gleb Natapov authored
Mask irq notifier list is already there. Signed-off-by:
-
Gleb Natapov authored
Signed-off-by:
-
Gleb Natapov authored
Maintain back mapping from irqchip/pin to gsi to speedup interrupt acknowledgment notifications. [avi: build fix on non-x86/ia64] Signed-off-by:
-
Gleb Natapov authored
Use gsi indexed array instead of scanning all entries on each interrupt injection. Signed-off-by:
-
