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path: root/drivers/kvm/kvm_main.c
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2007-07-16KVM: Use CPU_DYING for disabling virtualizationAvi Kivity
Only at the CPU_DYING stage can we be sure that no user process will be scheduled onto the cpu and oops when trying to use virtualization extensions. Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-07-16KVM: Tune hotplug/suspend IPIsAvi Kivity
The hotplug IPIs can be called from the cpu on which we are currently running on, so use on_cpu(). Similarly, drop on_each_cpu() for the suspend/resume callbacks, as we're in atomic context here and only one cpu is up anyway. Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-07-16KVM: Keep track of which cpus have virtualization enabledAvi Kivity
By keeping track of which cpus have virtualization enabled, we prevent double-enable or double-disable during hotplug, which is a very fatal oops. Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-07-16KVM: Clean up #includesAvi Kivity
Remove unnecessary ones, and rearange the remaining in the standard order. Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-07-16KVM: Remove kvmfs in favor of the anonymous inodes sourceAvi Kivity
kvm uses a pseudo filesystem, kvmfs, to generate inodes, a job that the new anonymous inodes source does much better. Cc: Davide Libenzi <davidel@xmailserver.org> Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-07-16KVM: Avoid useless memory write when possibleLuca Tettamanti
When writing to normal memory and the memory area is unchanged the write can be safely skipped, avoiding the costly kvm_mmu_pte_write. Signed-Off-By: Luca Tettamanti <kronos.it@gmail.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-07-16KVM: Add support for in-kernel pio handlersEddie Dong
Useful for the PIC and PIT. Signed-off-by: Yaozu (Eddie) Dong <eddie.dong@intel.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-07-16KVM: Adds support for in-kernel mmio handlersGregory Haskins
Signed-off-by: Gregory Haskins <ghaskins@novell.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-07-16KVM: Flush remote tlbs when reducing shadow pte permissionsAvi Kivity
When a vcpu causes a shadow tlb entry to have reduced permissions, it must also clear the tlb on remote vcpus. We do that by: - setting a bit on the vcpu that requests a tlb flush before the next entry - if the vcpu is currently executing, we send an ipi to make sure it exits before we continue Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-07-16KVM: Keep an upper bound of initialized vcpusAvi Kivity
That way, we don't need to loop for KVM_MAX_VCPUS for a single vcpu vm. Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-07-16KVM: Move duplicate halt handling code into kvm_main.cAvi Kivity
Will soon have a thid user. Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-07-16KVM: Fix adding an smp virtual machine to the vm listAvi Kivity
If we add the vm once per vcpu, we corrupt the list if the guest has multiple vcpus. Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-07-16KVM: Fix vcpu freeing for guest smpAvi Kivity
A vcpu can pin up to four mmu shadow pages, which means the freeing loop will never terminate. Fix by first unpinning shadow pages on all vcpus, then freeing shadow pages. Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-07-16KVM: Remove unnecessary initialization and checks in mark_page_dirty()Nguyen Anh Quynh
Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-07-16KVM: MMU: Use slab caches for shadow pages and their headersAvi Kivity
Use slab caches instead of a simple custom list. Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-07-16KVM: VMX: Avoid saving and restoring msr_efer on lightweight vmexitEddie Dong
MSR_EFER.LME/LMA bits are automatically save/restored by VMX hardware, KVM only needs to save NX/SCE bits at time of heavy weight VM Exit. But clearing NX bits in host envirnment may cause system hang if the host page table is using EXB bits, thus we leave NX bits as it is. If Host NX=1 and guest NX=0, we can do guest page table EXB bits check before inserting a shadow pte (though no guest is expecting to see this kind of gp fault). If host NX=0, we present guest no Execute-Disable feature to guest, thus no host NX=0, guest NX=1 combination. This patch reduces raw vmexit time by ~27%. Me: fix compile warnings on i386. Signed-off-by: Yaozu (Eddie) Dong <eddie.dong@intel.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-07-16KVM: Implement IA32_EBL_CR_POWERON msrMatthew Gregan
Attempting to boot the default 'bsd' kernel of OpenBSD 4.1 i386 in a guest fails early in the kernel init inside p3_get_bus_clock while trying to read the IA32_EBL_CR_POWERON MSR. KVM logs an 'unhandled MSR' message and the guest kernel faults. This patch is sufficient to allow OpenBSD to boot, after which it seems to run fine. I'm not sure if this is the correct solution for dealing with this particular MSR, but it works for me. Signed-off-by: Matthew Gregan <kinetik@flim.org> Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-07-16KVM: Unify kvm_mmu_pre_write() and kvm_mmu_post_write()Avi Kivity
Instead of calling two functions and repeating expensive checks, call one function and provide it with before/after information. Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-07-16KVM: Avoid saving and restoring some host CPU state on lightweight vmexitAvi Kivity
Many msrs and the like will only be used by the host if we schedule() or return to userspace. Therefore, we avoid saving them if we handle the exit within the kernel, and if a reschedule is not requested. Based on a patch from Eddie Dong <eddie.dong@intel.com> with a couple of fixes by me. Signed-off-by: Yaozu(Eddie) Dong <eddie.dong@intel.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-06-15KVM: Prevent guest fpu state from leaking into the hostAvi Kivity
The lazy fpu changes did not take into account that some vmexit handlers can sleep. Move loading the guest state into the inner loop so that it can be reloaded if necessary, and move loading the host state into vmx_vcpu_put() so it can be performed whenever we relinquish the vcpu. Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-05-21Detach sched.h from mm.hAlexey Dobriyan
First thing mm.h does is including sched.h solely for can_do_mlock() inline function which has "current" dereference inside. By dealing with can_do_mlock() mm.h can be detached from sched.h which is good. See below, why. This patch a) removes unconditional inclusion of sched.h from mm.h b) makes can_do_mlock() normal function in mm/mlock.c c) exports can_do_mlock() to not break compilation d) adds sched.h inclusions back to files that were getting it indirectly. e) adds less bloated headers to some files (asm/signal.h, jiffies.h) that were getting them indirectly Net result is: a) mm.h users would get less code to open, read, preprocess, parse, ... if they don't need sched.h b) sched.h stops being dependency for significant number of files: on x86_64 allmodconfig touching sched.h results in recompile of 4083 files, after patch it's only 3744 (-8.3%). Cross-compile tested on all arm defconfigs, all mips defconfigs, all powerpc defconfigs, alpha alpha-up arm i386 i386-up i386-defconfig i386-allnoconfig ia64 ia64-up m68k mips parisc parisc-up powerpc powerpc-up s390 s390-up sparc sparc-up sparc64 sparc64-up um-x86_64 x86_64 x86_64-up x86_64-defconfig x86_64-allnoconfig as well as my two usual configs. Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-09Add suspend-related notifications for CPU hotplugRafael J. Wysocki
Since nonboot CPUs are now disabled after tasks and devices have been frozen and the CPU hotplug infrastructure is used for this purpose, we need special CPU hotplug notifications that will help the CPU-hotplug-aware subsystems distinguish normal CPU hotplug events from CPU hotplug events related to a system-wide suspend or resume operation in progress. This patch introduces such notifications and causes them to be used during suspend and resume transitions. It also changes all of the CPU-hotplug-aware subsystems to take these notifications into consideration (for now they are handled in the same way as the corresponding "normal" ones). [oleg@tv-sign.ru: cleanups] Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Cc: Gautham R Shenoy <ego@in.ibm.com> Cc: Pavel Machek <pavel@ucw.cz> Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-03KVM: Don't require explicit indication of completion of mmio or pioAvi Kivity
It is illegal not to return from a pio or mmio request without completing it, as mmio or pio is an atomic operation. Therefore, we can simplify the userspace interface by avoiding the completion indication. Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-05-03KVM: Remove extraneous guest entry on mmio readAvi Kivity
When emulating an mmio read, we actually emulate twice: once to determine the physical address of the mmio, and, after we've exited to userspace to get the mmio value, we emulate again to place the value in the result register and update any flags. But we don't really need to enter the guest again for that, only to take an immediate vmexit. So, if we detect that we're doing an mmio read, emulate a single instruction before entering the guest again. Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-05-03KVM: VMX: Properly shadow the CR0 register in the vcpu structAnthony Liguori
Set all of the host mask bits for CR0 so that we can maintain a proper shadow of CR0. This exposes CR0.TS, paving the way for lazy fpu handling. Signed-off-by: Anthony Liguori <aliguori@us.ibm.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-05-03KVM: Allow passing 64-bit values to the emulated read/write APIAvi Kivity
This simplifies the API somewhat (by eliminating the special-case cmpxchg8b on i386). Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-05-03KVM: Per-vcpu statisticsAvi Kivity
Make the exit statistics per-vcpu instead of global. This gives a 3.5% boost when running one virtual machine per core on my two socket dual core (4 cores total) machine. Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-05-03KVM: VMX: Avoid unnecessary vcpu_load()/vcpu_put() cyclesYaozu Dong
By checking if a reschedule is needed, we avoid dropping the vcpu. [With changes by me, based on Anthony Liguori's observations] Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-05-03KVM: Handle guest page faults when emulating mmioAvi Kivity
Usually, guest page faults are detected by the kvm page fault handler, which detects if they are shadow faults, mmio faults, pagetable faults, or normal guest page faults. However, in ceratin circumstances, we can detect a page fault much later. One of these events is the following combination: - A two memory operand instruction (e.g. movsb) is executed. - The first operand is in mmio space (which is the fault reported to kvm) - The second operand is in an ummaped address (e.g. a guest page fault) The Windows 2000 installer does such an access, an promptly hangs. Fix by adding the missing page fault injection on that path. Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-05-03KVM: Use slab caches to allocate mmu data structuresAvi Kivity
Better leak detection, statistics, memory use, speed -- goodness all around. Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-05-03KVM: Initialize cr0 to indicate an fpu is presentAvi Kivity
Solaris panics if it sees a cpu with no fpu, and it seems to rely on this bit. Closes sourceforge bug 1698920. Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-05-03KVM: Add fpu get/set operationsAvi Kivity
These are really helpful when migrating an floating point app to another machine. Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-05-03KVM: Add physical memory aliasing featureAvi Kivity
With this, we can specify that accesses to one physical memory range will be remapped to another. This is useful for the vga window at 0xa0000 which is used as a movable window into the (much larger) framebuffer. Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-05-03KVM: Simply gfn_to_page()Avi Kivity
Mapping a guest page to a host page is a common operation. Currently, one has first to find the memory slot where the page belongs (gfn_to_memslot), then locate the page itself (gfn_to_page()). This is clumsy, and also won't work well with memory aliases. So simplify gfn_to_page() not to require memory slot translation first, and instead do it internally. Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-05-03KVM: Handle writes to MCG_STATUS msrSergey Kiselev
Some older (~2.6.7) kernels write MCG_STATUS register during kernel boot (mce_clear_all() function, called from mce_init()). It's not currently handled by kvm and will cause it to inject a GPF. Following patch adds a "nop" handler for this. Signed-off-by: Sergey Kiselev <sergey.kiselev@intel.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-05-03KVM: Modify guest segments after potentially switching modesAvi Kivity
The SET_SREGS ioctl modifies both cr0.pe (real mode/protected mode) and guest segment registers. Since segment handling is modified by the mode on Intel procesors, update the segment registers after the mode switch has taken place. Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-05-03KVM: Remove set_cr0_no_modeswitch() arch opAvi Kivity
set_cr0_no_modeswitch() was a hack to avoid corrupting segment registers. As we now cache the protected mode values on entry to real mode, this isn't an issue anymore, and it interferes with reboot (which usually _is_ a modeswitch). Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-05-03KVM: Avoid guest virtual addresses in string pio userspace interfaceAvi Kivity
The current string pio interface communicates using guest virtual addresses, relying on userspace to translate addresses and to check permissions. This interface cannot fully support guest smp, as the check needs to take into account two pages at one in case an unaligned string transfer straddles a page boundary. Change the interface not to communicate guest addresses at all; instead use a buffer page (mmaped by userspace) and do transfers there. The kernel manages the virtual to physical translation and can perform the checks atomically by taking the appropriate locks. Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-05-03KVM: Future-proof argument-less ioctlsAvi Kivity
Some ioctls ignore their arguments. By requiring them to be zero now, we allow a nonzero value to have some special meaning in the future. Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-05-03KVM: Allow kernel to select size of mmap() bufferAvi Kivity
This allows us to store offsets in the kernel/user kvm_run area, and be sure that userspace has them mapped. As offsets can be outside the kvm_run struct, userspace has no way of knowing how much to mmap. Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-05-03KVM: Add guest mode signal maskAvi Kivity
Allow a special signal mask to be used while executing in guest mode. This allows signals to be used to interrupt a vcpu without requiring signal delivery to a userspace handler, which is quite expensive. Userspace still receives -EINTR and can get the signal via sigwait(). Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-05-03KVM: Fold kvm_run::exit_type into kvm_run::exit_reasonAvi Kivity
Currently, userspace is told about the nature of the last exit from the guest using two fields, exit_type and exit_reason, where exit_type has just two enumerations (and no need for more). So fold exit_type into exit_reason, reducing the complexity of determining what really happened. Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-05-03KVM: Allow userspace to process hypercalls which have no kernel handlerAvi Kivity
This is useful for paravirtualized graphics devices, for example. Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-05-03KVM: Add method to check for backwards-compatible API extensionsAvi Kivity
Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-05-03KVM: Remove the 'emulated' field from the userspace interfaceAvi Kivity
We no longer emulate single instructions in userspace. Instead, we service mmio or pio requests. Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-05-03KVM: Handle cpuid in the kernel instead of punting to userspaceAvi Kivity
KVM used to handle cpuid by letting userspace decide what values to return to the guest. We now handle cpuid completely in the kernel. We still let userspace decide which values the guest will see by having userspace set up the value table beforehand (this is necessary to allow management software to set the cpu features to the least common denominator, so that live migration can work). The motivation for the change is that kvm kernel code can be impacted by cpuid features, for example the x86 emulator. Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-05-03KVM: Do not communicate to userspace through cpu registers during PIOAvi Kivity
Currently when passing the a PIO emulation request to userspace, we rely on userspace updating %rax (on 'in' instructions) and %rsi/%rdi/%rcx (on string instructions). This (a) requires two extra ioctls for getting and setting the registers and (b) is unfriendly to non-x86 archs, when they get kvm ports. So fix by doing the register fixups in the kernel and passing to userspace only an abstract description of the PIO to be done. Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-05-03KVM: Use a shared page for kernel/user communication when runing a vcpuAvi Kivity
Instead of passing a 'struct kvm_run' back and forth between the kernel and userspace, allocate a page and allow the user to mmap() it. This reduces needless copying and makes the interface expandable by providing lots of free space. Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-05-03KVM: Use own minor numberAvi Kivity
Use the minor number (232) allocated to kvm by lanana. Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-05-03KVM: Fix guest register corruption on paravirt hypercallDor Laor
The hypercall code mixes up the ->cache_regs() and ->decache_regs() callbacks, resulting in guest register corruption. Signed-off-by: Dor Laor <dor.laor@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com>