Suggested-by: NAvi Kivity <avi@redhat.com>
Signed-off-by: NRaghavendra K T <raghavendra.kt@linux.vnet.ibm.com>
Reviewed-by: NMarcelo Tosatti <mtosatti@redhat.com>
Reviewed-by: NRik van Riel <riel@redhat.com>
Tested-by: Christian Borntraeger <borntraeger@de.ibm.com> # on s390x
Signed-off-by: NAvi Kivity <avi@redhat.com>

This reverts commit fbd24153.

This commit is subtly buggy: kstrto*int() can return an error but
it's not checked in every path. simple_strtoul() on the other hand
could not fail, so this patch subtly intruduces new failure modes.
Signed-off-by: NShuah Khan <shuahkhan@gmail.com>
Link: http://lkml.kernel.org/r/1338424803.3569.5.camel@lorien2Signed-off-by: NIngo Molnar <mingo@kernel.org>

Use PIC_NUM_PINS instead of hard-coded 16 for pic pins.
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

When more than 1 source id is in use for the same GSI, we have the
following race related to handling irq_states race:

CPU 0 clears bit 0. CPU 0 read irq_state as 0. CPU 1 sets level to 1.
CPU 1 calls kvm_ioapic_set_irq(1). CPU 0 calls kvm_ioapic_set_irq(0).
Now ioapic thinks the level is 0 but irq_state is not 0.

Fix by performing all irq_states bitmap handling under pic/ioapic lock.
This also removes the need for atomics with irq_states handling.
Reported-by: NGleb Natapov <gleb@redhat.com>
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

Signed-off-by: NGuo Chao <yan@linux.vnet.ibm.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

Signed-off-by: NGuo Chao <yan@linux.vnet.ibm.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

Signed-off-by: NGuo Chao <yan@linux.vnet.ibm.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

Signed-off-by: NGuo Chao <yan@linux.vnet.ibm.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

Signed-off-by: NGuo Chao <yan@linux.vnet.ibm.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

Signed-off-by: NGuo Chao <yan@linux.vnet.ibm.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

Signed-off-by: NGuo Chao <yan@linux.vnet.ibm.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

Signed-off-by: NGeert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

The parameter, 'kvm', is not used in gfn_to_pfn_memslot, we can happily remove
it
Signed-off-by: NXiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

Using get_fault_pfn to cleanup the code
Signed-off-by: NXiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

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: NXiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

fix:
[  132.474633] 3.5.0-rc1+ #50 Not tainted
[  132.474634] -------------------------------
[  132.474635] include/linux/kvm_host.h:369 suspicious rcu_dereference_check() usage!
[  132.474636]
[  132.474636] other info that might help us debug this:
[  132.474636]
[  132.474638]
[  132.474638] rcu_scheduler_active = 1, debug_locks = 1
[  132.474640] 1 lock held by qemu-kvm/2832:
[  132.474657]  #0:  (&vcpu->mutex){+.+.+.}, at: [<ffffffffa01e1636>] vcpu_load+0x1e/0x91 [kvm]
[  132.474658]
[  132.474658] stack backtrace:
[  132.474660] Pid: 2832, comm: qemu-kvm Not tainted 3.5.0-rc1+ #50
[  132.474661] Call Trace:
[  132.474665]  [<ffffffff81092f40>] lockdep_rcu_suspicious+0xfc/0x105
[  132.474675]  [<ffffffffa01e0c85>] kvm_memslots+0x6d/0x75 [kvm]
[  132.474683]  [<ffffffffa01e0ca1>] gfn_to_memslot+0x14/0x4c [kvm]
[  132.474693]  [<ffffffffa01e3575>] mark_page_dirty+0x17/0x2a [kvm]
[  132.474706]  [<ffffffffa01f21ea>] kvm_arch_vcpu_ioctl+0xbcf/0xc07 [kvm]

Actually, we do not write vcpu->arch.time at this time, mark_page_dirty
should be removed.
Signed-off-by: NXiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

When populate pages across a mem boundary at bootup, the page count
populated isn't correct. This is due to mem populated to non-mem
region and ignored.

Pfn range is also wrongly aligned when mem boundary isn't page aligned.

For a dom0 booted with dom_mem=3368952K(0xcd9ff000-4k) dmesg diff is:
 [    0.000000] Freeing 9e-100 pfn range: 98 pages freed
 [    0.000000] 1-1 mapping on 9e->100
 [    0.000000] 1-1 mapping on cd9ff->100000
 [    0.000000] Released 98 pages of unused memory
 [    0.000000] Set 206435 page(s) to 1-1 mapping
-[    0.000000] Populating cd9fe-cda00 pfn range: 1 pages added
+[    0.000000] Populating cd9fe-cd9ff pfn range: 1 pages added
+[    0.000000] Populating 100000-100061 pfn range: 97 pages added
 [    0.000000] BIOS-provided physical RAM map:
 [    0.000000] Xen: 0000000000000000 - 000000000009e000 (usable)
 [    0.000000] Xen: 00000000000a0000 - 0000000000100000 (reserved)
 [    0.000000] Xen: 0000000000100000 - 00000000cd9ff000 (usable)
 [    0.000000] Xen: 00000000cd9ffc00 - 00000000cda53c00 (ACPI NVS)
...
 [    0.000000] Xen: 0000000100000000 - 0000000100061000 (usable)
 [    0.000000] Xen: 0000000100061000 - 000000012c000000 (unusable)
...
 [    0.000000] MEMBLOCK configuration:
...
-[    0.000000]  reserved[0x4]       [0x000000cd9ff000-0x000000cd9ffbff], 0xc00 bytes
-[    0.000000]  reserved[0x5]       [0x00000100000000-0x00000100060fff], 0x61000 bytes

Related xen memory layout:
(XEN) Xen-e820 RAM map:
(XEN)  0000000000000000 - 000000000009ec00 (usable)
(XEN)  00000000000f0000 - 0000000000100000 (reserved)
(XEN)  0000000000100000 - 00000000cd9ffc00 (usable)
Signed-off-by: NZhenzhong Duan <zhenzhong.duan@oracle.com>
[v2: If xen_do_chunk fail(populate), abort this chunk and any others]
Suggested by David, thanks.
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

Currently kexec in a PVonHVM guest fails with a triple fault because the
new kernel overwrites the shared info page. The exact failure depends on
the size of the kernel image. This patch moves the pfn from RAM into
MMIO space before the kexec boot.

The pfn containing the shared_info is located somewhere in RAM. This
will cause trouble if the current kernel is doing a kexec boot into a
new kernel. The new kernel (and its startup code) can not know where the
pfn is, so it can not reserve the page. The hypervisor will continue to
update the pfn, and as a result memory corruption occours in the new
kernel.

One way to work around this issue is to allocate a page in the
xen-platform pci device's BAR memory range. But pci init is done very
late and the shared_info page is already in use very early to read the
pvclock. So moving the pfn from RAM to MMIO is racy because some code
paths on other vcpus could access the pfn during the small   window when
the old pfn is moved to the new pfn. There is even a  small window were
the old pfn is not backed by a mfn, and during that time all reads
return -1.

Because it is not known upfront where the MMIO region is located it can
not be used right from the start in xen_hvm_init_shared_info.

To minimise trouble the move of the pfn is done shortly before kexec.
This does not eliminate the race because all vcpus are still online when
the syscore_ops will be called. But hopefully there is no work pending
at this point in time. Also the syscore_op is run last which reduces the
risk further.
Signed-off-by: NOlaf Hering <olaf@aepfle.de>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

init_hvm_pv_info is called only in PVonHVM context, move it into ifdef.
init_hvm_pv_info does not fail, make it a void function.
remove arguments from init_hvm_pv_info because they are not used by the
caller.
Signed-off-by: NOlaf Hering <olaf@aepfle.de>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

Both have type struct shared_info so no cast is needed.
Signed-off-by: NOlaf Hering <olaf@aepfle.de>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

When switching tasks in a Xen PV guest, avoid updating the TLS
descriptors if they haven't changed.  This improves the speed of
context switches by almost 10% as much of the time the descriptors are
the same or only one is different.

The descriptors written into the GDT by Xen are modified from the
values passed in the update_descriptor hypercall so we keep shadow
copies of the three TLS descriptors to compare against.

lmbench3 test     Before  After  Improvement
--------------------------------------------
lat_ctx -s 32 24   7.19    6.52  9%
lat_pipe          12.56   11.66  7%
Signed-off-by: NDavid Vrabel <david.vrabel@citrix.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

Signed-off-by: NDavid Vrabel <david.vrabel@citrix.com>
[v1: Moving it to the Xen file]
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

When constructing the initial page tables, if the MFN for a usable PFN
is missing in the p2m then that frame is initially ballooned out.  In
this case, zero the PTE (as in decrease_reservation() in
drivers/xen/balloon.c).

This is obviously safe instead of having an valid PTE with an MFN of
INVALID_P2M_ENTRY (~0).
Signed-off-by: NDavid Vrabel <david.vrabel@citrix.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

In xen_set_pte() if batching is unavailable (because the caller is in
an interrupt context such as handling a page fault) it would fall back
to using native_set_pte() and trapping and emulating the PTE write.

On 32-bit guests this requires two traps for each PTE write (one for
each dword of the PTE).  Instead, do one mmu_update hypercall
directly.

During construction of the initial page tables, continue to use
native_set_pte() because most of the PTEs being set are in writable
and unpinned pages (see phys_pmd_init() in arch/x86/mm/init_64.c) and
using a hypercall for this is very expensive.

This significantly improves page fault performance in 32-bit PV
guests.

lmbench3 test  Before    After     Improvement
----------------------------------------------
lat_pagefault  3.18 us   2.32 us   27%
lat_proc fork  356 us    313.3 us  11%
Signed-off-by: NDavid Vrabel <david.vrabel@citrix.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

When Xen hypervisor inject vMCE to guest, use native mce handler
to handle it
Signed-off-by: NKe, Liping <liping.ke@intel.com>
Signed-off-by: NJiang, Yunhong <yunhong.jiang@intel.com>
Signed-off-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: NLiu, Jinsong <jinsong.liu@intel.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

there are 3 funcs which need to be _initcalled in a logic sequence:
1. xen_late_init_mcelog
2. mcheck_init_device
3. threshold_init_device

xen_late_init_mcelog must register xen_mce_chrdev_device before
native mce_chrdev_device registration if running under xen platform;

mcheck_init_device should be inited before threshold_init_device to
initialize mce_device, otherwise a a NULL ptr dereference will cause panic.

so we use following _initcalls
1. device_initcall(xen_late_init_mcelog);
2. device_initcall_sync(mcheck_init_device);
3. late_initcall(threshold_init_device);

when running under xen, the initcall order is 1,2,3;
on baremetal, we skip 1 and we do only 2 and 3.
Acked-and-tested-by: NBorislav Petkov <bp@amd64.org>
Suggested-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: NLiu, Jinsong <jinsong.liu@intel.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

When MCA error occurs, it would be handled by Xen hypervisor first,
and then the error information would be sent to initial domain for logging.

This patch gets error information from Xen hypervisor and convert
Xen format error into Linux format mcelog. This logic is basically
self-contained, not touching other kernel components.

By using tools like mcelog tool users could read specific error information,
like what they did under native Linux.

To test follow directions outlined in Documentation/acpi/apei/einj.txt
Acked-and-tested-by: NBorislav Petkov <borislav.petkov@amd.com>
Signed-off-by: NKe, Liping <liping.ke@intel.com>
Signed-off-by: NJiang, Yunhong <yunhong.jiang@intel.com>
Signed-off-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: NLiu, Jinsong <jinsong.liu@intel.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

Signed-off-by: NAvi Kivity <avi@redhat.com>
Signed-off-by: NMarcelo 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: NTakuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: NMarcelo 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: NTakuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

This is needed to push trace_kvm_age_page() into kvm_age_rmapp() in the
following patch.
Signed-off-by: NTakuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: NMarcelo 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: NTakuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: NMarcelo 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: NTakuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Cc: Alexander Graf <agraf@suse.de>
Cc: Paul Mackerras <paulus@samba.org>
Signed-off-by: NMarcelo 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: NTakuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Cc: Alexander Graf <agraf@suse.de>
Cc: Paul Mackerras <paulus@samba.org>
Signed-off-by: NMarcelo 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: NTakuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Cc: Alexander Graf <agraf@suse.de>
Cc: Paul Mackerras <paulus@samba.org>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

We can treat every level uniformly.
Signed-off-by: NTakuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

This reverts commit f9808b7f.
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: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Use apic_set_eoi_write, apic_write to avoid meedling in core apic
driver data structures directly.
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: NAvi 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: NMichael S. Tsirkin <mst@redhat.com>
Acked-by: NIngo Molnar <mingo@kernel.org>
Signed-off-by: NAvi Kivity <avi@redhat.com>

vsyscall_seccomp introduced a dependency on __secure_computing.  On
configurations with CONFIG_SECCOMP disabled, compilation will fail.
Reported-by: Nfeng xiangjun <fengxj325@gmail.com>
Signed-off-by: NWill Drewry <wad@chromium.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>