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path: root/drivers/kvm
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2007-05-03KVM: MMU: Remove unnecessary check for pdptr accessAvi Kivity
We already special case the pdptr access, so no need to check it again. 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: Initialize the apic_base msr on svm tooAvi Kivity
Older userspace didn't care, but newer userspace (with the cpuid changes) does. Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-05-03KVM: Add a special exit reason when exiting due to an interruptAvi Kivity
This is redundant, as we also return -EINTR from the ioctl, but it allows us to examine the exit_reason field on resume without seeing old data. 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: Fix bogus sign extension in mmu mapping auditAvi Kivity
When auditing a 32-bit guest on a 64-bit host, sign extension of the page table directory pointer table index caused bogus addresses to be shown on audit errors. Fix by declaring the index unsigned. 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: Use the generic skip_emulated_instruction() in hypercall codeDor Laor
Instead of twiddling the rip registers directly, use the skip_emulated_instruction() function to do that for us. Signed-off-by: Dor Laor <dor.laor@qumranet.com> 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>
2007-04-19KVM: Fix off-by-one when writing to a nonpae guest pdeAvi Kivity
Nonpae guest pdes are shadowed by two pae ptes, so we double the offset twice: once to account for the pte size difference, and once because we need to shadow pdes for a single guest pde. But when writing to the upper guest pde we also need to truncate the lower bits, otherwise the multiply shifts these bits into the pde index and causes an access to the wrong shadow pde. If we're at the end of the page (accessing the very last guest pde) we can even overflow into the next host page and oops. Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-03-27KVM: always reload segment selectorsIngo Molnar
failed VM entry on VMX might still change %fs or %gs, thus make sure that KVM always reloads the segment selectors. This is crutial on both x86 and x86_64: x86 has __KERNEL_PDA in %fs on which things like 'current' depends and x86_64 has 0 there and needs MSR_GS_BASE to work. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-03-27KVM: Prevent system selectors leaking into guest on real->protected mode ↵Avi Kivity
transition on vmx Intel virtualization extensions do not support virtualizing real mode. So kvm uses virtualized vm86 mode to run real mode code. Unfortunately, this virtualized vm86 mode does not support the so called "big real" mode, where the segment selector and base do not agree with each other according to the real mode rules (base == selector << 4). To work around this, kvm checks whether a selector/base pair violates the virtualized vm86 rules, and if so, forces it into conformance. On a transition back to protected mode, if we see that the guest did not touch a forced segment, we restore it back to the original protected mode value. This pile of hacks breaks down if the gdt has changed in real mode, as it can cause a segment selector to point to a system descriptor instead of a normal data segment. In fact, this happens with the Windows bootloader and the qemu acpi bios, where a protected mode memcpy routine issues an innocent 'pop %es' and traps on an attempt to load a system descriptor. "Fix" by checking if the to-be-restored selector points at a system segment, and if so, coercing it into a normal data segment. The long term solution, of course, is to abandon vm86 mode and use emulation for big real mode. Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-03-18KVM: MMU: Fix host memory corruption on i386 with >= 4GB ramAvi Kivity
PAGE_MASK is an unsigned long, so using it to mask physical addresses on i386 (which are 64-bit wide) leads to truncation. This can result in page->private of unrelated memory pages being modified, with disasterous results. Fix by not using PAGE_MASK for physical addresses; instead calculate the correct value directly from PAGE_SIZE. Also fix a similar BUG_ON(). Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-03-18KVM: MMU: Fix guest writes to nonpae pdeAvi Kivity
KVM shadow page tables are always in pae mode, regardless of the guest setting. This means that a guest pde (mapping 4MB of memory) is mapped to two shadow pdes (mapping 2MB each). When the guest writes to a pte or pde, we intercept the write and emulate it. We also remove any shadowed mappings corresponding to the write. Since the mmu did not account for the doubling in the number of pdes, it removed the wrong entry, resulting in a mismatch between shadow page tables and guest page tables, followed shortly by guest memory corruption. This patch fixes the problem by detecting the special case of writing to a non-pae pde and adjusting the address and number of shadow pdes zapped accordingly. Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-03-18KVM: Fix guest sysenter on vmxAvi Kivity
The vmx code currently treats the guest's sysenter support msrs as 32-bit values, which breaks 32-bit compat mode userspace on 64-bit guests. Fix by using the native word width of the machine. Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-03-18KVM: Unset kvm_arch_ops if arch module loading failedAvi Kivity
Otherwise, the core module thinks the arch module is loaded, and won't let you reload it after you've fixed the bug. Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-03-04KVM: Move kvmfs magic number to <linux/magic.h>Andrew Morton
Use the standard magic.h for kvmfs. Cc: Avi Kivity <avi@qumranet.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-03-04KVM: Fix bogus failure in kvm.ko module initializationAvi Kivity
A bogus 'return r' can cause an otherwise successful module load to fail. This both denies users the use of kvm, and it also denies them the use of their machine, as it leaves a filesystem registered with its callbacks pointing into now-freed module memory. Fix by returning a zero like a good module. Thanks to Richard Lucassen <mailinglists@lucassen.org> (?) for reporting the problem and for providing access to a machine which exhibited it. Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-03-04KVM: Remove write access permissions when dirty-page-logging is enabledUri Lublin
Enabling dirty page logging is done using KVM_SET_MEMORY_REGION ioctl. If the memory region already exists, we need to remove write accesses, so writes will be caught, and dirty pages will be logged. Signed-off-by: Uri Lublin <uril@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-03-04kvm: move do_remove_write_access() upUri Lublin
To be called from kvm_vm_ioctl_set_memory_region() Signed-off-by: Uri Lublin <uril@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-03-04KVM: Fix dirty page log bitmap size/access calculationUri Lublin
Since dirty_bitmap is an unsigned long array, the alignment and size need to take that into account. Signed-off-by: Uri Lublin <uril@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-03-04KVM: Add missing calls to mark_page_dirty()Uri Lublin
A few places where we modify guest memory fail to call mark_page_dirty(), causing live migration to fail. This adds the missing calls. Signed-off-by: Uri Lublin <uril@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-03-04KVM: Per-vcpu inodesAvi Kivity
Allocate a distinct inode for every vcpu in a VM. This has the following benefits: - the filp cachelines are no longer bounced when f_count is incremented on every ioctl() - the API and internal code are distinctly clearer; for example, on the KVM_GET_REGS ioctl, there is no need to copy the vcpu number from userspace and then copy the registers back; the vcpu identity is derived from the fd used to make the call Right now the performance benefits are completely theoretical since (a) we don't support more than one vcpu per VM and (b) virtualization hardware inefficiencies completely everwhelm any cacheline bouncing effects. But both of these will change, and we need to prepare the API today. Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-03-04KVM: Move kvm_vm_ioctl_create_vcpu() aroundAvi Kivity
In preparation of some hacking. Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-03-04KVM: Rename some kvm_dev_ioctl_*() functions to kvm_vm_ioctl_*()Avi Kivity
This reflects the changed scope, from device-wide to single vm (previously every device open created a virtual machine). Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-03-04KVM: Create an inode per virtual machineAvi Kivity
This avoids having filp->f_op and the corresponding inode->i_fop different, which is a little unorthodox. The ioctl list is split into two: global kvm ioctls and per-vm ioctls. A new ioctl, KVM_CREATE_VM, is used to create VMs and return the VM fd. Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-03-04KVM: Add internal filesystem for generating inodesAvi Kivity
The kvmfs inodes will represent virtual machines and vcpus, as necessary, reducing cacheline bouncing due to inodes and filps being shared. Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-03-04KVM: More 0 -> NULL conversionsAvi Kivity
Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-03-04KVM: SVM: intercept SMI to handle it at host levelJoerg Roedel
This patch changes the SVM code to intercept SMIs and handle it outside the guest. Signed-off-by: Joerg Roedel <joerg.roedel@amd.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-03-04KVM: svm: init cr0 with the wp bit setAvi Kivity
Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-03-04KVM: Wire up hypercall handlers to a central arch-independent locationAvi Kivity
Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-03-04KVM: Add hypercall host support for svmAvi Kivity
Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-03-04KVM: Add host hypercall support for vmxIngo Molnar
Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-03-04KVM: add MSR based hypercall APIIngo Molnar
This adds a special MSR based hypercall API to KVM. This is to be used by paravirtual kernels and virtual drivers. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-03-04KVM: Use page_private()/set_page_private() apisMarkus Rechberger
Besides using an established api, this allows using kvm in older kernels. Signed-off-by: Markus Rechberger <markus.rechberger@amd.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-03-04KVM: Use ARRAY_SIZE macro instead of manual calculation.Ahmed S. Darwish
Signed-off-by: Ahmed S. Darwish <darwish.07@gmail.com> Signed-off-by: Dor Laor <dor.laor@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-03-04KVM: vmx: hack set_cr0_no_modeswitch() to actually do modeswitchJoerg Roedel
The whole thing is rotten, but this allows vmx to boot with the guest reboot fix. Signed-off-by: Markus Rechberger <markus.rechberger@amd.com> Signed-off-by: Joerg Roedel <joerg.roedel@amd.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-03-04KVM: CosmeticsAvi Kivity
Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-03-04KVM: Move virtualization deactivation from CPU_DEAD state to CPU_DOWN_PREPAREJeremy Katz
This gives it more chances of surviving suspend. Signed-off-by: Jeremy Katz <katzj@redhat.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-03-04KVM: mmu: add missing dirty page tracking casesAvi Kivity
We fail to mark a page dirty in three cases: - setting the accessed bit in a pte - setting the dirty bit in a pte - emulating a write into a pagetable This fix adds the missing cases. Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-02-13[PATCH] i386: Convert i386 PDA code to use %fsJeremy Fitzhardinge
Convert the PDA code to use %fs rather than %gs as the segment for per-processor data. This is because some processors show a small but measurable performance gain for reloading a NULL segment selector (as %fs generally is in user-space) versus a non-NULL one (as %gs generally is). On modern processors the difference is very small, perhaps undetectable. Some old AMD "K6 3D+" processors are noticably slower when %fs is used rather than %gs; I have no idea why this might be, but I think they're sufficiently rare that it doesn't matter much. This patch also fixes the math emulator, which had not been adjusted to match the changed struct pt_regs. [frederik.deweerdt@gmail.com: fixit with gdb] [mingo@elte.hu: Fix KVM too] Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com> Signed-off-by: Andi Kleen <ak@suse.de> Cc: Ian Campbell <Ian.Campbell@XenSource.com> Acked-by: Ingo Molnar <mingo@elte.hu> Acked-by: Zachary Amsden <zach@vmware.com> Cc: Eric Dumazet <dada1@cosmosbay.com> Signed-off-by: Frederik Deweerdt <frederik.deweerdt@gmail.com> Signed-off-by: Andrew Morton <akpm@osdl.org>