It will trigger a WARN_ON if the page has been freed but it is still
used in mmu, it can help us to detect mm bug early
Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
When we invalidate a THP page, we call the handler with the same
rmap_pde argument 512 times in the following loop:
for each guest page in the range
for each level
unmap using rmap
This patch avoids these extra handler calls by changing the loop order
like this:
for each level
for each rmap in the range
unmap using rmap
With the preceding patches in the patch series, this made THP page
invalidation more than 5 times faster on our x86 host: the host became
more responsive during swapping the guest's memory as a result.
Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
This restricts the tracing to page aging and makes it possible to
optimize kvm_handle_hva_range() further in the following patch.
Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
This is needed to push trace_kvm_age_page() into kvm_age_rmapp() in the
following patch.
Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
This makes it possible to loop over rmap_pde arrays in the same way as
we do over rmap so that we can optimize kvm_handle_hva_range() easily in
the following patch.
Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
When we tested KVM under memory pressure, with THP enabled on the host,
we noticed that MMU notifier took a long time to invalidate huge pages.
Since the invalidation was done with mmu_lock held, it not only wasted
the CPU but also made the host harder to respond.
This patch mitigates this by using kvm_handle_hva_range().
Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Cc: Alexander Graf <agraf@suse.de>
Cc: Paul Mackerras <paulus@samba.org>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
When guest's memory is backed by THP pages, MMU notifier needs to call
kvm_unmap_hva(), which in turn leads to kvm_handle_hva(), in a loop to
invalidate a range of pages which constitute one huge page:
for each page
for each memslot
if page is in memslot
unmap using rmap
This means although every page in that range is expected to be found in
the same memslot, we are forced to check unrelated memslots many times.
If the guest has more memslots, the situation will become worse.
Furthermore, if the range does not include any pages in the guest's
memory, the loop over the pages will just consume extra time.
This patch, together with the following patches, solves this problem by
introducing kvm_handle_hva_range() which makes the loop look like this:
for each memslot
for each page in memslot
unmap using rmap
In this new processing, the actual work is converted to a loop over rmap
which is much more cache friendly than before.
Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Cc: Alexander Graf <agraf@suse.de>
Cc: Paul Mackerras <paulus@samba.org>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
This restricts hva handling in mmu code and makes it easier to extend
kvm_handle_hva() so that it can treat a range of addresses later in this
patch series.
Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Cc: Alexander Graf <agraf@suse.de>
Cc: Paul Mackerras <paulus@samba.org>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
We can treat every level uniformly.
Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
This reverts commit f9808b7fd4.
After commit 'kvm: switch to apic_set_eoi_write, apic_write'
the stubs are no longer needed as kvm does not look at apicdrivers anymore.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Use apic_set_eoi_write, apic_write to avoid meedling in core apic
driver data structures directly.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
KVM PV EOI optimization overrides eoi_write apic op with its own
version. Add an API for this to avoid meddling with core x86 apic driver
data structures directly.
For KVM use, we don't need any guarantees about when the switch to the
new op will take place, so it could in theory use this API after SMP init,
but it currently doesn't, and restricting callers to early init makes it
clear that it's safe as it won't race with actual APIC driver use.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Avi Kivity <avi@redhat.com>
ppc queue from Alex Graf:
* Prepare some of the booke code for 64 bit support
* BookE: Fix ESR flag in DSI
* BookE: Add rfci emulation
* 'for-upstream' of git://github.com/agraf/linux-2.6:
KVM: PPC: Critical interrupt emulation support
KVM: PPC: e500mc: Fix tlbilx emulation for 64-bit guests
KVM: PPC64: booke: Set interrupt computation mode for 64-bit host
KVM: PPC: bookehv: Add ESR flag to Data Storage Interrupt
KVM: PPC: bookehv64: Add support for std/ld emulation.
booke: Added crit/mc exception handler for e500v2
booke/bookehv: Add host crit-watchdog exception support
Signed-off-by: Avi Kivity <avi@redhat.com>
This patch handles PCID/INVPCID for guests.
Process-context identifiers (PCIDs) are a facility by which a logical processor
may cache information for multiple linear-address spaces so that the processor
may retain cached information when software switches to a different linear
address space. Refer to section 4.10.1 in IA32 Intel Software Developer's Manual
Volume 3A for details.
For guests with EPT, the PCID feature is enabled and INVPCID behaves as running
natively.
For guests without EPT, the PCID feature is disabled and INVPCID triggers #UD.
Signed-off-by: Junjie Mao <junjie.mao@intel.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
While debugging I noticed that unlike all the other hypervisor code in the
kernel, kvm does not have an entry for x86_hyper which is used in
detect_hypervisor_platform() which results in a nice printk in the
syslog. This is only really a stub function but it
does make kvm more consistent with the other hypervisors.
Signed-off-by: Prarit Bhargava <prarit@redhat.com>
Cc: Avi Kivity <avi@redhat.com>
Cc: Gleb Natapov <gleb@redhat.com>
Cc: Alex Williamson <alex.williamson@redhat.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Marcelo Tostatti <mtosatti@redhat.com>
Cc: kvm@vger.kernel.org
Signed-off-by: Avi Kivity <avi@redhat.com>
rfci instruction and CSRR0/1 registers are emulated.
Signed-off-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Stuart Yoder <stuart.yoder@freescale.com>
Signed-off-by: Bharat Bhushan <bharat.bhushan@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
tlbilxva emulation was using an u32 variable for guest effective address.
Replace it with gva_t type to handle 64-bit guests.
Signed-off-by: Mihai Caraman <mihai.caraman@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
64-bit host needs to remain in 64-bit mode when an exception take place.
Set interrupt computaion mode in EPCR register.
Signed-off-by: Mihai Caraman <mihai.caraman@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
ESR register is required by Data Storage Interrupt handling code.
Add the specific flag to the interrupt handler.
Signed-off-by: Mihai Caraman <mihai.caraman@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
Watchdog is taken at critical exception level. So this patch
is tested with host watchdog exception happening when guest
is running.
Signed-off-by: Bharat Bhushan <bharat.bhushan@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
Document fast page fault and mmu-lock in locking.txt
Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
The P bit of page fault error code is missed in this tracepoint, fix it by
passing the full error code
Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
To see what happen on this path and help us to optimize it
Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
If the the present bit of page fault error code is set, it indicates
the shadow page is populated on all levels, it means what we do is
only modify the access bit which can be done out of mmu-lock
Currently, in order to simplify the code, we only fix the page fault
caused by write-protect on the fast path
Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
This bit indicates whether the spte can be writable on MMU, that means
the corresponding gpte is writable and the corresponding gfn is not
protected by shadow page protection
In the later path, SPTE_MMU_WRITEABLE will indicates whether the spte
can be locklessly updated
Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
mmu_spte_update() is the common function, we can easily audit the path
Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Export the present bit of page fault error code, the later patch
will use it
Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Use __drop_large_spte to cleanup this function and comment spte_write_protect
Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Introduce a common function to abstract spte write-protect to
cleanup the code
Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
The reture value of __rmap_write_protect is either 1 or 0, use
true/false instead of these
Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Our emulation should be complete enough that we can emulate guests
while they are in big real mode, or in a mode transition that is not
virtualizable without unrestricted guest support.
Signed-off-by: Avi Kivity <avi@redhat.com>
Guest software doesn't actually depend on it, but vmx will refuse us
entry if we don't. Set the bit in both the cached segment and memory,
just to be nice.
Signed-off-by: Avi Kivity <avi@redhat.com>
Opcode C8.
Only ENTER with lexical nesting depth 0 is implemented, since others are
very rare. We'll fail emulation if nonzero lexical depth is used so data
is not corrupted.
Signed-off-by: Avi Kivity <avi@redhat.com>
Commit 2adb5ad9fe removed ByteOp from MOVZX/MOVSX, replacing them by
SrcMem8, but neglected to fix the dependency in the emulation code
on ByteOp. This caused the instruction not to have any effect in
some circumstances.
Fix by replacing the check for ByteOp with the equivalent src.op_bytes == 1.
Signed-off-by: Avi Kivity <avi@redhat.com>
If we return early from an invalid guest state emulation loop, make
sure we return to it later if the guest state is still invalid.
Signed-off-by: Avi Kivity <avi@redhat.com>
Checking EFLAGS.IF is incorrect as we might be in interrupt shadow. If
that is the case, the main loop will notice that and not inject the interrupt,
causing an endless loop.
Fix by using vmx_interrupt_allowed() to check if we can inject an interrupt
instead.
Signed-off-by: Avi Kivity <avi@redhat.com>
We correctly default to SS when BP is used as a base in 16-bit address mode,
but we don't do that for 32-bit mode.
Fix by adjusting the default to SS when either ESP or EBP is used as the base
register.
Signed-off-by: Avi Kivity <avi@redhat.com>
memop is not initialized; this can lead to a two-byte operation
following a 4-byte operation to see garbage values. Usually
truncation fixes things fot us later on, but at least in one case
(call abs) it doesn't.
Fix by moving memop to the auto-initialized field area.
Signed-off-by: Avi Kivity <avi@redhat.com>
Xiao Guangrong