Avi Kivity [Mon, 21 Jun 2010 07:57:45 +0000 (10:57 +0300)]
KVM: Prevent internal slots from being COWed
If a process with a memory slot is COWed, the page will change its address
(despite having an elevated reference count). This breaks internal memory
slots which have their physical addresses loaded into vmcs registers (see
the APIC access memory slot).
Newer (guest) kernels use sigp sense running in their spinlock
implementation to check if the other cpu is running before yielding
the processor. This revealed some wrong guest settings, causing
unnecessary exits for every sigp sense running.
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Avi Kivity <avi@redhat.com>
Wei Yongjun [Thu, 17 Jun 2010 09:33:55 +0000 (17:33 +0800)]
KVM: x86 emulator: fix group3 instruction decoding
Group 3 instruction with ModRM reg field as 001 is
defined as test instruction under AMD arch, and
emulate_grp3() is ready for emulate it, so fix the
decoding.
static inline int emulate_grp3(...)
{
...
switch (c->modrm_reg) {
case 0 ... 1: /* test */
emulate_2op_SrcV("test", c->src, c->dst, ctxt->eflags);
...
}
Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com> Signed-off-by: Avi Kivity <avi@redhat.com>
Asias He [Sat, 19 Jun 2010 08:52:12 +0000 (16:52 +0800)]
KVM: PPC: fix uninitialized variable warning in kvm_ppc_core_deliver_interrupts
Fixes:
arch/powerpc/kvm/booke.c: In function 'kvmppc_core_deliver_interrupts':
arch/powerpc/kvm/booke.c:147: warning: 'msr_mask' may be used uninitialized in this function
Signed-off-by: Asias He <asias.hejun@gmail.com> Signed-off-by: Avi Kivity <avi@redhat.com>
Chris Lalancette [Wed, 16 Jun 2010 21:11:11 +0000 (17:11 -0400)]
KVM: x86: Introduce a workqueue to deliver PIT timer interrupts
We really want to "kvm_set_irq" during the hrtimer callback,
but that is risky because that is during interrupt context.
Instead, offload the work to a workqueue, which is a bit safer
and should provide most of the same functionality.
Signed-off-by: Chris Lalancette <clalance@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Xiao Guangrong [Fri, 11 Jun 2010 13:35:15 +0000 (21:35 +0800)]
KVM: MMU: don't walk every parent pages while mark unsync
While we mark the parent's unsync_child_bitmap, if the parent is already
unsynced, it no need walk it's parent, it can reduce some unnecessary
workload
Xiao Guangrong [Fri, 11 Jun 2010 13:34:04 +0000 (21:34 +0800)]
KVM: MMU: clear unsync_child_bitmap completely
In current code, some page's unsync_child_bitmap is not cleared completely
in mmu_sync_children(), for example, if two PDPEs shard one PDT, one of
PDPE's unsync_child_bitmap is not cleared.
Currently, it not harm anything just little overload, but it's the prepare
work for the later patch
Denis Kirjanov [Fri, 11 Jun 2010 11:23:26 +0000 (11:23 +0000)]
KVM: PPC: fix build warning in kvm_arch_vcpu_ioctl_run
Fix compile warning:
CC [M] arch/powerpc/kvm/powerpc.o
arch/powerpc/kvm/powerpc.c: In function 'kvm_arch_vcpu_ioctl_run':
arch/powerpc/kvm/powerpc.c:290: warning: 'gpr' may be used uninitialized in this function
arch/powerpc/kvm/powerpc.c:290: note: 'gpr' was declared here
Xiao Guangrong [Tue, 8 Jun 2010 12:07:01 +0000 (20:07 +0800)]
KVM: MMU: delay local tlb flush
delay local tlb flush until enter guest moden, it can reduce vpid flush
frequency and reduce remote tlb flush IPI(if KVM_REQ_TLB_FLUSH bit is
already set, IPI is not sent)
Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> Signed-off-by: Avi Kivity <avi@redhat.com>
Xiao Guangrong [Fri, 4 Jun 2010 13:54:38 +0000 (21:54 +0800)]
KVM: MMU: don't get free page number in the loop
In the later patch, we will modify sp's zapping way like below:
kvm_mmu_prepare_zap_page A
kvm_mmu_prepare_zap_page B
kvm_mmu_prepare_zap_page C
....
kvm_mmu_commit_zap_page
[ zaped multiple sps only need to call kvm_mmu_commit_zap_page once ]
In __kvm_mmu_free_some_pages() function, the free page number is
getted form 'vcpu->kvm->arch.n_free_mmu_pages' in loop, it will
hinders us to apply kvm_mmu_prepare_zap_page() and kvm_mmu_commit_zap_page()
since kvm_mmu_prepare_zap_page() not free sp.
Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> Signed-off-by: Avi Kivity <avi@redhat.com>
Mohammed Gamal [Mon, 31 May 2010 19:40:54 +0000 (22:40 +0300)]
KVM: VMX: Properly return error to userspace on vmentry failure
The vmexit handler returns KVM_EXIT_UNKNOWN since there is no handler
for vmentry failures. This intercepts vmentry failures and returns
KVM_FAIL_ENTRY to userspace instead.
Signed-off-by: Mohammed Gamal <m.gamal005@gmail.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Zachary Amsden [Thu, 27 May 2010 01:09:43 +0000 (15:09 -1000)]
KVM: SVM: Fix EFER.LME being stripped
Must set VCPU register to be the guest notion of EFER even if that
setting is not valid on hardware. This was masked by the set in
set_efer until 7657fd5ace88e8092f5f3a84117e093d7b893f26 broke that.
Fix is simply to set the VCPU register before stripping bits.
Signed-off-by: Zachary Amsden <zamsden@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
Lai Jiangshan [Wed, 26 May 2010 08:48:19 +0000 (16:48 +0800)]
KVM: MMU: calculate correct gfn for small host pages backing large guest pages
In Documentation/kvm/mmu.txt:
gfn:
Either the guest page table containing the translations shadowed by this
page, or the base page frame for linear translations. See role.direct.
But in function FNAME(fetch)(), sp->gfn is incorrect when one of following
situations occurred:
1) guest is 32bit paging and the guest PDE maps a 4-MByte page
(backed by 4k host pages), FNAME(fetch)() miss handling the quadrant.
And if guest use pse-36, "table_gfn = gpte_to_gfn(gw->ptes[level - delta]);"
is incorrect.
2) guest is long mode paging and the guest PDPTE maps a 1-GByte page
(backed by 4k or 2M host pages).
So we fix it to suit to the document and suit to the code which
requires sp->gfn correct when sp->role.direct=1.
We use the goal mapping gfn(gw->gfn) to calculate the base page frame
for linear translations, it is simple and easy to be understood.
Reported-by: Marcelo Tosatti <mtosatti@redhat.com> Reported-by: Gui Jianfeng <guijianfeng@cn.fujitsu.com> Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Signed-off-by: Avi Kivity <avi@redhat.com>
Lai Jiangshan [Wed, 26 May 2010 08:48:25 +0000 (16:48 +0800)]
KVM: MMU: Calculate correct base gfn for direct non-DIR level
In Document/kvm/mmu.txt:
gfn:
Either the guest page table containing the translations shadowed by this
page, or the base page frame for linear translations. See role.direct.
But in __direct_map(), the base gfn calculation is incorrect,
it does not calculate correctly when level=3 or 4.
Fix by using PT64_LVL_ADDR_MASK() which accounts for all levels correctly.
Reported-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Signed-off-by: Avi Kivity <avi@redhat.com>
Lai Jiangshan [Wed, 26 May 2010 08:49:59 +0000 (16:49 +0800)]
KVM: MMU: Don't allocate gfns page for direct mmu pages
When sp->role.direct is set, sp->gfns does not contain any essential
information, leaf sptes reachable from this sp are for a continuous
guest physical memory range (a linear range).
So sp->gfns[i] (if it was set) equals to sp->gfn + i. (PT_PAGE_TABLE_LEVEL)
Obviously, it is not essential information, we can calculate it when need.
It means we don't need sp->gfns when sp->role.direct=1,
Thus we can save one page usage for every kvm_mmu_page.
Note:
Access to sp->gfns must be wrapped by kvm_mmu_page_get_gfn()
or kvm_mmu_page_set_gfn().
It is only exposed in FNAME(sync_page).
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Signed-off-by: Avi Kivity <avi@redhat.com>
Xiao Guangrong [Mon, 24 May 2010 07:41:33 +0000 (15:41 +0800)]
KVM: MMU: allow more page become unsync at getting sp time
Allow more page become asynchronous at getting sp time, if need create new
shadow page for gfn but it not allow unsync(level > 1), we should unsync all
gfn's unsync page
Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> Signed-off-by: Avi Kivity <avi@redhat.com>
Xiao Guangrong [Mon, 24 May 2010 07:40:07 +0000 (15:40 +0800)]
KVM: MMU: allow more page become unsync at gfn mapping time
In current code, shadow page can become asynchronous only if one
shadow page for a gfn, this rule is too strict, in fact, we can
let all last mapping page(i.e, it's the pte page) become unsync,
and sync them at invlpg or flush tlb time.
This patch allow more page become asynchronous at gfn mapping time
Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> Signed-off-by: Avi Kivity <avi@redhat.com>
Xiao Guangrong [Sat, 15 May 2010 10:52:34 +0000 (18:52 +0800)]
KVM: MMU: don't write-protect if have new mapping to unsync page
Two cases maybe happen in kvm_mmu_get_page() function:
- one case is, the goal sp is already in cache, if the sp is unsync,
we only need update it to assure this mapping is valid, but not
mark it sync and not write-protect sp->gfn since it not broke unsync
rule(one shadow page for a gfn)
- another case is, the goal sp not existed, we need create a new sp
for gfn, i.e, gfn (may)has another shadow page, to keep unsync rule,
we should sync(mark sync and write-protect) gfn's unsync shadow page.
After enabling multiple unsync shadows, we sync those shadow pages
only when the new sp not allow to become unsync(also for the unsyc
rule, the new rule is: allow all pte page become unsync)
Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> Signed-off-by: Avi Kivity <avi@redhat.com>
Alex Williamson [Wed, 12 May 2010 13:46:31 +0000 (09:46 -0400)]
KVM: remove CAP_SYS_RAWIO requirement from kvm_vm_ioctl_assign_irq
Remove this check in an effort to allow kvm guests to run without
root privileges. This capability check doesn't seem to add any
security since the device needs to have already been added via the
assign device ioctl and the io actually occurs through the pci
sysfs interface.
Signed-off-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Dongxiao Xu [Tue, 11 May 2010 10:29:45 +0000 (18:29 +0800)]
KVM: VMX: VMCLEAR/VMPTRLD usage changes
Originally VMCLEAR/VMPTRLD is called on vcpu migration. To
support hosted VMM coexistance, VMCLEAR is executed on vcpu
schedule out, and VMPTRLD is executed on vcpu schedule in.
This could also eliminate the IPI when doing VMCLEAR.
Avi Kivity [Mon, 10 May 2010 09:09:56 +0000 (12:09 +0300)]
KVM: MMU: Fix free memory accounting race in mmu_alloc_roots()
We drop the mmu lock between freeing memory and allocating the roots; this
allows some other vcpu to sneak in and allocate memory.
While the race is benign (resulting only in temporary overallocation, not oom)
it is simple and easy to fix by moving the freeing close to the allocation.
Signed-off-by: Avi Kivity <avi@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Gleb Natapov [Mon, 10 May 2010 08:16:56 +0000 (11:16 +0300)]
KVM: inject #UD if instruction emulation fails and exit to userspace
Do not kill VM when instruction emulation fails. Inject #UD and report
failure to userspace instead. Userspace may choose to reenter guest if
vcpu is in userspace (cpl == 3) in which case guest OS will kill
offending process and continue running.