This adds a heuristic for speeding up revocation of write access to
pagetables for HIGHPTE linux kernels, which previously had to brute-force
search all L1 shadows.
Signed-off-by: Tim Deegan <Tim.Deegan@xensource.com>
Holding pages readonly that have guest PAE l3 tables in them means
a performance hit and potential bug if the guest puts other
datastructures on the same page as an l3 table. Instead of shadowing
them, treat PAE guests as if they had four CR3 registers, and load all
four top-level entries when we handle a CR3 write. This also cuts about
500 lines of special-case refcounting and re-copying code.
Signed-off-by: Tim Deegan <Tim.Deegan@xensource.com>
If a guest writes a "bad" pagetable entry and we fail to unshadow the
page, don't kill the guest. This makes the behaviour the same as
if the bad PTE were already in place when we shadowed the page.
Signed-off-by: Tim Deegan <Tim.Deegan@xensource.com>
Fix code limiting XENOPROF_get_buffer and XENOPROF_set_passive
argument max_samples so that no more than MAX_OPROF_SHARED_PAGES are
used.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
The qemu device model hangs when a non-existent floppy file is passed
via 'fda' or 'fdb'. The attached patch checks whether the floppy file
exists and raises an error if it does not.
Signed-off-by: Stefan Berger <stefanb@us.ibm.com>
to watch for creation of the handle node in xenstore, as it is
written by xend when creating the backend directory as part of
the same transaction.
Signed-off-by: Keir Fraser <keir@xensource.com>
Newer BIOS implementations will be able to disable the SVM feature,
although an additional test of an MSR (VMCR 0xC0010114 bit 4) is
necessary (set equals disabled). Bit 4 of MSR 0xc0010114 returns 0
(SVM enabled) on machines with older BIOS' without the SVM disable
feature support.
Signed-off-by: Wei Huang <wei.huang2@amd.com>=20
Signed-off-by: Tom Woller <thomas.woller@amd.com>=20
We need to make a copy of data from tx_ring before
verifying them as otherwise what we end up using may
be different from what was verified.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
since both xend and the xenstore-* utilities used in the hotplug
scripts can easily reach the limit and we trust them anyway.
Signed-off-by: Christian Limpach <Christian.Limpach@xensource.com>
This fixes a crash under mmstress in SMP linux guests, where one vcpu
could remove shadow entries when another was reading them for invlpg.
Signed-off-by: Tim Deegan <Tim.Deegan@xensource.com>
Normally, we can leave the contents of shadows in place when we destroy
them, but this is not the case for l3 subshadows, since they do not get
zeroed on reallocation unless the entire l3 page is unshadowed.
This fixes several crashes seen with SMP PAE HVM RHEL4.2 guests.
Signed-off-by: Tim Deegan <Tim.Deegan@xensource.com>
The guest OS should be capable of parsing an image file in
whatever format was produced by that OS's tools. Furthermore,
we have seen initrd images with trailing garbage. This causes
us to calculate the wrong size for the uncompressed data and hence
fail to build the guest.
Signed-off-by: Keir Fraser <keir@xensource.com>
First, auto-translate guests can use remap_pfn_range() rather than
direct_remap_pfn_range(). This actually works better because
remap_pfn_range() can legitimately assert VM_PFNMAP (this patch
removes this flag for direct_remap_pfn_range().
There are various cleanups and fixes to the privcmd interface:
1. VMAs should be searched and used under the mmap semaphore
2. Mapping should be single shot (since cirect_remap_pfn_range()
expects the PTEs to be empty when it is called).
3. Demand-fault population of the privcmd vma should be disallowed.
4. Various others, including a more thorough check of input args.
Signed-off-by: Keir Fraser <keir@xensource.com>
so we should always do shadow_update_paging_modes() before we writes to
GUEST_CR3 with v->arch.hvm_vcpu.hw_cr3.
Signed-off-by: Xiaohui Xin xiaohui.xin@intel.com
Signed-off-by: Xin Li <xin.b.li@intel.com>
Although in the correct spirit, it seems there is some other
dependency in the code that assumes ExtInts are queued until
thay can be immediately delivered (EFLAGS.IF==1). This patch
therefore caused instability in Linux guests.
Signed-off-by: Keir Fraser <keir@xensource.com>
