linux.git/drivers/kvm, branch v2.6.20

[PATCH] KVM: fix lockup on 32-bit intel hosts with nx disabled in the bios

2007-02-02T00:22:41+00:00

Intel hosts, without long mode, and with nx support disabled in the bios
have an efer that is readable but not writable.  This causes a lockup on
switch to guest mode (even though it should exit with reason 34 according
to the documentation).

Signed-off-by: Avi Kivity 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] Fix "CONFIG_X86_64_" typo in drivers/kvm/svm.c

2007-01-30T16:26:45+00:00

Fix what looks like an obvious typo in the file drivers/kvm/svm.c.

Signed-off-by: Robert P. J. Day 
Acked-by: Avi Kivity 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] KVM: SVM: Propagate cpu shutdown events to userspace

2007-01-26T21:50:57+00:00

This patch implements forwarding of SHUTDOWN intercepts from the guest on to
userspace on AMD SVM.  A SHUTDOWN event occurs when the guest produces a
triple fault (e.g.  on reboot).  This also fixes the bug that a guest reboot
actually causes a host reboot under some circumstances.

Signed-off-by: Joerg Roedel 
Signed-off-by: Avi Kivity 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] KVM: MMU: Report nx faults to the guest

2007-01-26T21:50:57+00:00

With the recent guest page fault change, we perform access checks on our
own instead of relying on the cpu.  This means we have to perform the nx
checks as well.

Software like the google toolbar on windows appears to rely on this
somehow.

Signed-off-by: Avi Kivity 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] KVM: MMU: Perform access checks in walk_addr()

2007-01-26T21:50:57+00:00

Check pte permission bits in walk_addr(), instead of scattering the checks all
over the code.  This has the following benefits:

1. We no longer set the accessed bit for accessed which fail permission checks.
2. Setting the accessed bit is simplified.
3. Under some circumstances, we used to pretend a page fault was fixed when
   it would actually fail the access checks.  This caused an unnecessary
   vmexit.
4. The error code for guest page faults is now correct.

The fix helps netbsd further along booting, and allows kvm to pass the new mmu
testsuite.

Signed-off-by: Avi Kivity 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] KVM: Emulate IA32_MISC_ENABLE msr

2007-01-26T21:50:57+00:00

This allows netbsd 3.1 i386 to get further along installing.

Signed-off-by: Avi Kivity 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] KVM: SVM: Fix SVM idt confusion

2007-01-26T21:50:57+00:00

There's an obvious typo in svm_{get,set}_idt, causing it to access the ldt
instead.

Because these functions are only called for save/load on AMD, the bug does not
impact normal operation.  With the fix, save/load works as expected on AMD
hosts.

Signed-off-by: Uri Lublin 
Signed-off-by: Avi Kivity 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] KVM: fix bogus pagefault on writable pages

2007-01-23T15:52:06+00:00

If a page is marked as dirty in the guest pte, set_pte_common() can set the
writable bit on newly-instantiated shadow pte.  This optimization avoids
a write fault after the initial read fault.

However, if a write fault instantiates the pte, fix_write_pf() incorrectly
reports the fault as a guest page fault, and the guest oopses on what appears
to be a correctly-mapped page.

Fix is to detect the condition and only report a guest page fault on a user
access to a kernel page.

With the fix, a kvm guest can survive a whole night of running the kernel
hacker's screensaver (make -j9 in a loop).

Signed-off-by: Avi Kivity 
Cc: Ingo Molnar 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] KVM: x86 emulator: fix bit string instructions

2007-01-23T15:52:06+00:00

The various bit string instructions (bts, btc, etc.) fail to adjust the
address correctly if the bit address is beyond BITS_PER_LONG.

This bug creeped in as the emulator originally relied on cr2 to contain the
memory address; however we now decode it from the mod r/m bits, and must
adjust the offset to account for large bit indices.

The patch is rather large because it switches src and dst decoding around, so
that the bit index is available when decoding the memory address.

This fixes workloads like the FC5 installer.

Signed-off-by: Avi Kivity 
Cc: Ingo Molnar 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] KVM: fix race between mmio reads and injected interrupts

2007-01-23T15:52:06+00:00

The kvm mmio read path looks like:

 1. guest read faults
 2. kvm emulates read, calls emulator_read_emulated()
 3. fails as a read requires userspace help
 4. exit to userspace
 5. userspace emulates read, kvm sets vcpu->mmio_read_completed
 6. re-enter guest, fault again
 7. kvm emulates read, calls emulator_read_emulated()
 8. succeeds as vcpu->mmio_read_emulated is set
 9. instruction completes and guest is resumed

A problem surfaces if the userspace exit (step 5) also requests an interrupt
injection.  In that case, the guest does not re-execute the original
instruction, but the interrupt handler.  The next time an mmio read is
exectued (likely for a different address), step 3 will find
vcpu->mmio_read_completed set and return the value read for the original
instruction.

The problem manifested itself in a few annoying ways:
- little squares appear randomly on console when switching virtual terminals
- ne2000 fails under nfs read load
- rtl8139 complains about "pci errors" even though the device model is
  incapable of issuing them.

Fix by skipping interrupt injection if an mmio read is pending.

A better fix is to avoid re-entry into the guest, and re-emulating immediately
instead.  However that's a bit more complex.

Signed-off-by: Avi Kivity 
Cc: Ingo Molnar 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds