As Eric said,
 "what we need to do is move the variable vmcoreinfo_note out of the
  kernel's .bss section. And modify the code to regenerate and keep this
  information in something like the control page.

  Definitely something like this needs a page all to itself, and ideally
  far away from any other kernel data structures. I clearly was not
  watching closely the data someone decided to keep this silly thing in
  the kernel's .bss section."

This patch allocates extra pages for these vmcoreinfo_XXX variables, one
advantage is that it enhances some safety of vmcoreinfo, because
vmcoreinfo now is kept far away from other kernel data structures.

Link: http://lkml.kernel.org/r/1493281021-20737-1-git-send-email-xlpang@redhat.comSigned-off-by: NXunlei Pang <xlpang@redhat.com>
Tested-by: NMichael Holzheu <holzheu@linux.vnet.ibm.com>
Reviewed-by: NJuergen Gross <jgross@suse.com>
Suggested-by: NEric Biederman <ebiederm@xmission.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Dave Young <dyoung@redhat.com>
Cc: Hari Bathini <hbathini@linux.vnet.ibm.com>
Cc: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Remove unnecessary variable mfn in function xen_foreach_remap_area() and,
refactor the code.

Variable mfn at line 518:mfn = xen_remap_buf.mfns[i];
is only being used to store a value to be passed as
an argument to the xen_update_mem_tables() function.
This value can be passed directly, which makes variable
mfn unnecessary. Also, value assigned to variable mfn
at line 534:mfn = xen_remap_mfn; is never used.

Addresses-Coverity-ID: 1260110
Signed-off-by: NGustavo A. R. Silva <garsilva@embeddedor.com>
Reviewed-by: NJuergen Gross <jgross@suse.com>
Signed-off-by: NJuergen Gross <jgross@suse.com>

In preparation for an objtool rewrite which will have broader checks,
whitelist functions and files which cause problems because they do
unusual things with the stack.

These whitelists serve as a TODO list for which functions and files
don't yet have undwarf unwinder coverage.  Eventually most of the
whitelists can be removed in favor of manual CFI hint annotations or
objtool improvements.
Signed-off-by: NJosh Poimboeuf <jpoimboe@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: live-patching@vger.kernel.org
Link: http://lkml.kernel.org/r/7f934a5d707a574bda33ea282e9478e627fb1829.1498659915.git.jpoimboe@redhat.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

In a HVM guest the kernel allocates the page for mapping the shared
info structure via extend_brk() today. This will lead to a drop of
performance as the underlying EPT entry will have to be split up into
4kB entries as the single shared info page is located in hypervisor
memory.

The issue has been detected by using the libmicro munmap test:
unmapping 8kB of memory was faster by nearly a factor of two when no
pv interfaces were active in the HVM guest.

So instead of taking a page from memory which might be mapped via
large EPT entries use a page which is already mapped via a 4kB EPT
entry: we can take a page from the first 1MB of memory as the video
memory at 640kB disallows using larger EPT entries.
Signed-off-by: NJuergen Gross <jgross@suse.com>
Reviewed-by: NBoris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: NJuergen Gross <jgross@suse.com>

The current approach, which is the wholesale efi struct initialization from
a 'efi_xen' local template is not robust. Usually if new member is defined
then it is properly initialized in drivers/firmware/efi/efi.c, but not in
arch/x86/xen/efi.c.

The effect is that the Xen initialization clears any fields the generic code
might have set and the Xen code does not know about yet.

I saw this happen a few times, so let's initialize only the EFI struct members
used by Xen and maintain no local duplicate, to avoid such issues in the future.
Signed-off-by: NDaniel Kiper <daniel.kiper@oracle.com>
Reviewed-by: NBoris Ostrovsky <boris.ostrovsky@oracle.com>
Acked-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: andrew.cooper3@citrix.com
Cc: jgross@suse.com
Cc: linux-efi@vger.kernel.org
Cc: matt@codeblueprint.co.uk
Cc: stable@vger.kernel.org
Cc: xen-devel@lists.xenproject.org
Link: http://lkml.kernel.org/r/1498128697-12943-3-git-send-email-daniel.kiper@oracle.com
[ Clarified the changelog. ]
Signed-off-by: NIngo Molnar <mingo@kernel.org>

All implementations of apic->cpu_mask_to_apicid_and() and the two incoming
cpumasks to search for the target.

Move that operation to the call site and rename it to cpu_mask_to_apicid()
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Christoph Hellwig <hch@lst.de>
Link: http://lkml.kernel.org/r/20170619235446.641575516@linutronix.de

ARM and x86 had duplicated versions of the dma_ops structure, the
only difference is that x86 hasn't wired up the set_dma_mask,
mmap, and get_sgtable ops yet.  On x86 all of them are identical
to the generic version, so they aren't needed but harmless.

All the symbols used only for xen_swiotlb_dma_ops can now be marked
static as well.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

On PVH, PVHVM, at failure in the VCPUOP_register_vcpu_info hypercall
we limit the number of cpus to to MAX_VIRT_CPUS. However, if this
failure had occurred for a cpu beyond MAX_VIRT_CPUS, we continue
to function with > MAX_VIRT_CPUS.

This leads to problems at the next save/restore cycle when there
are > MAX_VIRT_CPUS threads going into stop_machine() but coming
back up there's valid state for only the first MAX_VIRT_CPUS.

This patch pulls the excess CPUs down via cpu_down().
Reviewed-by: NBoris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: NAnkur Arora <ankur.a.arora@oracle.com>
Signed-off-by: NJuergen Gross <jgross@suse.com>

The hypercall VCPUOP_register_vcpu_info can fail. This failure is
handled by making per_cpu(xen_vcpu, cpu) point to its shared_info
slot and those without one (cpu >= MAX_VIRT_CPUS) be NULL.

For PVH/PVHVM, this is not enough, because we also need to pull
these VCPUs out of circulation.

Fix for PVH/PVHVM: on registration failure in the cpuhp prepare
callback (xen_cpu_up_prepare_hvm()), return an error to the cpuhp
state-machine so it can fail the CPU init.

Fix for PV: the registration happens before smp_init(), so, in the
failure case we clamp setup_max_cpus and limit the number of VCPUs
that smp_init() will bring-up to MAX_VIRT_CPUS.
This is functionally correct but it makes the code a bit simpler
if we get rid of this explicit clamping: for VCPUs that don't have
valid xen_vcpu, fail the CPU init in the cpuhp prepare callback
(xen_cpu_up_prepare_pv()).
Reviewed-by: NBoris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: NAnkur Arora <ankur.a.arora@oracle.com>
Signed-off-by: NJuergen Gross <jgross@suse.com>

If CONFIG_SMP is disabled, xen_setup_vcpu_info_placement() is called from
xen_setup_shared_info(). This is fine as far as boot goes, but it means
that we also call it in the restore path. This results in an OOPS
because we assign to pv_mmu_ops.read_cr2 which is __ro_after_init.

Also, though less problematically, this means we call xen_vcpu_setup()
twice at restore -- once from the vcpu info placement call and the
second time from xen_vcpu_restore().

Fix by calling xen_setup_vcpu_info_placement() at boot only.
Reviewed-by: NBoris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: NAnkur Arora <ankur.a.arora@oracle.com>
Signed-off-by: NJuergen Gross <jgross@suse.com>

When Xen restores a PVHVM or PVH guest, its shared_info only holds
up to 32 CPUs. The hypercall VCPUOP_register_vcpu_info allows
us to setup per-page areas for VCPUs. This means we can boot
PVH* guests with more than 32 VCPUs. During restore the per-cpu
structure is allocated freshly by the hypervisor (vcpu_info_mfn is
set to INVALID_MFN) so that the newly restored guest can make a
VCPUOP_register_vcpu_info hypercall.

However, we end up triggering this condition in Xen:
/* Run this command on yourself or on other offline VCPUS. */
 if ( (v != current) && !test_bit(_VPF_down, &v->pause_flags) )

which means we are unable to setup the per-cpu VCPU structures
for running VCPUS. The Linux PV code paths makes this work by
iterating over cpu_possible in xen_vcpu_restore() with:

 1) is target CPU up (VCPUOP_is_up hypercall?)
 2) if yes, then VCPUOP_down to pause it
 3) VCPUOP_register_vcpu_info
 4) if it was down, then VCPUOP_up to bring it back up

With Xen commit 192df6f9122d ("xen/x86: allow HVM guests to use
hypercalls to bring up vCPUs") this is available for non-PV guests.
As such first check if VCPUOP_is_up is actually possible before
trying this dance.

As most of this dance code is done already in xen_vcpu_restore()
let's make it callable on PV, PVH and PVHVM.
Based-on-patch-by: NKonrad Wilk <konrad.wilk@oracle.com>
Reviewed-by: NBoris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: NAnkur Arora <ankur.a.arora@oracle.com>
Signed-off-by: NJuergen Gross <jgross@suse.com>

Largely mechanical changes to aid unification of xen_vcpu_restore()
logic for PV, PVH and PVHVM.

xen_vcpu_setup(): the only change in logic is that clamp_max_cpus()
is now handled inside the "if (!xen_have_vcpu_info_placement)" block.

xen_vcpu_restore(): code movement from enlighten_pv.c to enlighten.c.

xen_vcpu_info_reset(): pulls together all the code where xen_vcpu
is set to default.
Reviewed-by: NBoris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: NAnkur Arora <ankur.a.arora@oracle.com>
Signed-off-by: NJuergen Gross <jgross@suse.com>

With CONFIG_X86_5LEVEL=y, level 4 is no longer top level of page tables.

Let's give these variable more generic names: init_top_pgt and
early_top_pgt.
Signed-off-by: NKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reviewed-by: NJuergen Gross <jgross@suse.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-arch@vger.kernel.org
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/20170606113133.22974-9-kirill.shutemov@linux.intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

The kernel has several code paths that read CR3.  Most of them assume that
CR3 contains the PGD's physical address, whereas some of them awkwardly
use PHYSICAL_PAGE_MASK to mask off low bits.

Add explicit mask macros for CR3 and convert all of the CR3 readers.
This will keep them from breaking when PCID is enabled.
Signed-off-by: NAndy Lutomirski <luto@kernel.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: xen-devel <xen-devel@lists.xen.org>
Link: http://lkml.kernel.org/r/883f8fb121f4616c1c1427ad87350bb2f5ffeca1.1497288170.git.luto@kernel.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>

Lazy TLB state is currently managed in a rather baroque manner.
AFAICT, there are three possible states:

 - Non-lazy.  This means that we're running a user thread or a
   kernel thread that has called use_mm().  current->mm ==
   current->active_mm == cpu_tlbstate.active_mm and
   cpu_tlbstate.state == TLBSTATE_OK.

 - Lazy with user mm.  We're running a kernel thread without an mm
   and we're borrowing an mm_struct.  We have current->mm == NULL,
   current->active_mm == cpu_tlbstate.active_mm, cpu_tlbstate.state
   != TLBSTATE_OK (i.e. TLBSTATE_LAZY or 0).  The current cpu is set
   in mm_cpumask(current->active_mm).  CR3 points to
   current->active_mm->pgd.  The TLB is up to date.

 - Lazy with init_mm.  This happens when we call leave_mm().  We
   have current->mm == NULL, current->active_mm ==
   cpu_tlbstate.active_mm, but that mm is only relelvant insofar as
   the scheduler is tracking it for refcounting.  cpu_tlbstate.state
   != TLBSTATE_OK.  The current cpu is clear in
   mm_cpumask(current->active_mm).  CR3 points to swapper_pg_dir,
   i.e. init_mm->pgd.

This patch simplifies the situation.  Other than perf, x86 stops
caring about current->active_mm at all.  We have
cpu_tlbstate.loaded_mm pointing to the mm that CR3 references.  The
TLB is always up to date for that mm.  leave_mm() just switches us
to init_mm.  There are no longer any special cases for mm_cpumask,
and switch_mm() switches mms without worrying about laziness.

After this patch, cpu_tlbstate.state serves only to tell the TLB
flush code whether it may switch to init_mm instead of doing a
normal flush.

This makes fairly extensive changes to xen_exit_mmap(), which used
to look a bit like black magic.

Perf is unchanged.  With or without this change, perf may behave a bit
erratically if it tries to read user memory in kernel thread context.
We should build on this patch to teach perf to never look at user
memory when cpu_tlbstate.loaded_mm != current->mm.
Signed-off-by: NAndy Lutomirski <luto@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Borislav Petkov <bpetkov@suse.de>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Nadav Amit <nadav.amit@gmail.com>
Cc: Nadav Amit <namit@vmware.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-mm@kvack.org
Signed-off-by: NIngo Molnar <mingo@kernel.org>

Rather than passing all the contents of flush_tlb_info to
flush_tlb_others(), pass a pointer to the structure directly. For
consistency, this also removes the unnecessary cpu parameter from
uv_flush_tlb_others() to make its signature match the other
*flush_tlb_others() functions.

This serves two purposes:

 - It will dramatically simplify future patches that change struct
   flush_tlb_info, which I'm planning to do.

 - struct flush_tlb_info is an adequate description of what to do
   for a local flush, too, so by reusing it we can remove duplicated
   code between local and remove flushes in a future patch.
Signed-off-by: NAndy Lutomirski <luto@kernel.org>
Acked-by: NRik van Riel <riel@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Borislav Petkov <bpetkov@suse.de>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Nadav Amit <nadav.amit@gmail.com>
Cc: Nadav Amit <namit@vmware.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-mm@kvack.org
[ Fix build warning. ]
Signed-off-by: NIngo Molnar <mingo@kernel.org>

xen_flush_tlb_all() is used in arch/x86/xen/mmu.c only. Make it static.
Signed-off-by: NJuergen Gross <jgross@suse.com>
Reviewed-by: NBoris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: NJuergen Gross <jgross@suse.com>

There are some leftovers testing for pvh guest mode in pv-only source
files. Remove them.
Signed-off-by: NJuergen Gross <jgross@suse.com>
Reviewed-by: NBoris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: NJuergen Gross <jgross@suse.com>

When booted as pv-guest the p2m list presented by the Xen is already
mapped to virtual addresses. In dom0 case the hypervisor might make use
of 2M- or 1G-pages for this mapping. Unfortunately while being properly
aligned in virtual and machine address space, those pages might not be
aligned properly in guest physical address space.

So when trying to obtain the guest physical address of such a page
pud_pfn() and pmd_pfn() must be avoided as those will mask away guest
physical address bits not being zero in this special case.
Signed-off-by: NJuergen Gross <jgross@suse.com>
Reviewed-by: NJan Beulich <jbeulich@suse.com>
Signed-off-by: NJuergen Gross <jgross@suse.com>

When running as Xen pv guest X86_BUG_SYSRET_SS_ATTRS must not be set
on AMD cpus.

This bug/feature bit is kind of special as it will be used very early
when switching threads. Setting the bit and clearing it a little bit
later leaves a critical window where things can go wrong. This time
window has enlarged a little bit by using setup_clear_cpu_cap() instead
of the hypervisor's set_cpu_features callback. It seems this larger
window now makes it rather easy to hit the problem.

The proper solution is to never set the bit in case of Xen.
Signed-off-by: NJuergen Gross <jgross@suse.com>
Reviewed-by: NBoris Ostrovsky <boris.ostrovsky@oracle.com>
Acked-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NJuergen Gross <jgross@suse.com>

Routines that are set by xen_init_time_ops() use shared_info's
pvclock_vcpu_time_info area. This area is not properly available until
shared_info is mapped in xen_setup_shared_info().

This became especially problematic due to commit dd759d93 ("x86/timers:
Add simple udelay calibration") where we end up reading tsc_to_system_mul
from xen_dummy_shared_info (i.e. getting zero value) and then trying
to divide by it in pvclock_tsc_khz().
Signed-off-by: NBoris Ostrovsky <boris.ostrovsky@oracle.com>
Reviewed-by: NJuergen Gross <jgross@suse.com>
Signed-off-by: NJuergen Gross <jgross@suse.com>

Commit 690b7f10b4f9f ("x86/xen: use capabilities instead of fake cpuid
values for xsave") introduced a regression as it tried to make use of
the fixup feature before it being available.

Fall back to the old variant testing via cpuid().
Signed-off-by: NJuergen Gross <jgross@suse.com>
Reviewed-by: NBoris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: NJuergen Gross <jgross@suse.com>

Commit 84d582d2 ("xen: Revert commits da72ff5b and
72a9b186") defined xen_have_vector_callback in enlighten_hvm.c.
Since guest-type-neutral code refers to this variable this causes
build failures when CONFIG_XEN_PVHVM is not defined.

Moving xen_have_vector_callback definition to enlighten.c resolves
this issue.
Signed-off-by: NBoris Ostrovsky <boris.ostrovsky@oracle.com>
Reported-by: NRandy Dunlap <rdunlap@infradead.org>
Acked-by: NRandy Dunlap <rdunlap@infradead.org>
Reviewed-by: NJuergen Gross <jgross@suse.com>
Signed-off-by: NJuergen Gross <jgross@suse.com>

When rebooting DOM0 with ACPI on ARM64, the kernel is crashing with the stack
trace [1].

This is happening because when EFI runtimes are enabled, the reset code
(see machine_restart) will first try to use EFI restart method.

However, the EFI restart code is expecting the reset_system callback to
be always set. This is not the case for Xen and will lead to crash.

The EFI restart helper is used in multiple places and some of them don't
not have fallback (see machine_power_off). So implement reset_system
callback as a call to xen_reboot when using EFI Xen.

[   36.999270] reboot: Restarting system
[   37.002921] Internal error: Attempting to execute userspace memory: 86000004 [#1] PREEMPT SMP
[   37.011460] Modules linked in:
[   37.014598] CPU: 0 PID: 1 Comm: systemd-shutdow Not tainted 4.11.0-rc1-00003-g1e248b60a39b-dirty #506
[   37.023903] Hardware name: (null) (DT)
[   37.027734] task: ffff800902068000 task.stack: ffff800902064000
[   37.033739] PC is at 0x0
[   37.036359] LR is at efi_reboot+0x94/0xd0
[   37.040438] pc : [<0000000000000000>] lr : [<ffff00000880f2c4>] pstate: 404001c5
[   37.047920] sp : ffff800902067cf0
[   37.051314] x29: ffff800902067cf0 x28: ffff800902068000
[   37.056709] x27: ffff000008992000 x26: 000000000000008e
[   37.062104] x25: 0000000000000123 x24: 0000000000000015
[   37.067499] x23: 0000000000000000 x22: ffff000008e6e250
[   37.072894] x21: ffff000008e6e000 x20: 0000000000000000
[   37.078289] x19: ffff000008e5d4c8 x18: 0000000000000010
[   37.083684] x17: 0000ffffa7c27470 x16: 00000000deadbeef
[   37.089079] x15: 0000000000000006 x14: ffff000088f42bef
[   37.094474] x13: ffff000008f42bfd x12: ffff000008e706c0
[   37.099870] x11: ffff000008e70000 x10: 0000000005f5e0ff
[   37.105265] x9 : ffff800902067a50 x8 : 6974726174736552
[   37.110660] x7 : ffff000008cc6fb8 x6 : ffff000008cc6fb0
[   37.116055] x5 : ffff000008c97dd8 x4 : 0000000000000000
[   37.121453] x3 : 0000000000000000 x2 : 0000000000000000
[   37.126845] x1 : 0000000000000000 x0 : 0000000000000000
[   37.132239]
[   37.133808] Process systemd-shutdow (pid: 1, stack limit = 0xffff800902064000)
[   37.141118] Stack: (0xffff800902067cf0 to 0xffff800902068000)
[   37.146949] 7ce0:                                   ffff800902067d40 ffff000008085334
[   37.154869] 7d00: 0000000000000000 ffff000008f3b000 ffff800902067d40 ffff0000080852e0
[   37.162787] 7d20: ffff000008cc6fb0 ffff000008cc6fb8 ffff000008c7f580 ffff000008c97dd8
[   37.170706] 7d40: ffff800902067d60 ffff0000080e2c2c 0000000000000000 0000000001234567
[   37.178624] 7d60: ffff800902067d80 ffff0000080e2ee8 0000000000000000 ffff0000080e2df4
[   37.186544] 7d80: 0000000000000000 ffff0000080830f0 0000000000000000 00008008ff1c1000
[   37.194462] 7da0: ffffffffffffffff 0000ffffa7c4b1cc 0000000000000000 0000000000000024
[   37.202380] 7dc0: ffff800902067dd0 0000000000000005 0000fffff24743c8 0000000000000004
[   37.210299] 7de0: 0000fffff2475f03 0000000000000010 0000fffff2474418 0000000000000005
[   37.218218] 7e00: 0000fffff2474578 000000000000000a 0000aaaad6b722c0 0000000000000001
[   37.226136] 7e20: 0000000000000123 0000000000000038 ffff800902067e50 ffff0000081e7294
[   37.234055] 7e40: ffff800902067e60 ffff0000081e935c ffff800902067e60 ffff0000081e9388
[   37.241973] 7e60: ffff800902067eb0 ffff0000081ea388 0000000000000000 00008008ff1c1000
[   37.249892] 7e80: ffffffffffffffff 0000ffffa7c4a79c 0000000000000000 ffff000000020000
[   37.257810] 7ea0: 0000010000000004 0000000000000000 0000000000000000 ffff0000080830f0
[   37.265729] 7ec0: fffffffffee1dead 0000000028121969 0000000001234567 0000000000000000
[   37.273651] 7ee0: ffffffffffffffff 8080000000800000 0000800000008080 feffa9a9d4ff2d66
[   37.281567] 7f00: 000000000000008e feffa9a9d5b60e0f 7f7fffffffff7f7f 0101010101010101
[   37.289485] 7f20: 0000000000000010 0000000000000008 000000000000003a 0000ffffa7ccf588
[   37.297404] 7f40: 0000aaaad6b87d00 0000ffffa7c4b1b0 0000fffff2474be0 0000aaaad6b88000
[   37.305326] 7f60: 0000fffff2474fb0 0000000001234567 0000000000000000 0000000000000000
[   37.313240] 7f80: 0000000000000000 0000000000000001 0000aaaad6b70d4d 0000000000000000
[   37.321159] 7fa0: 0000000000000001 0000fffff2474ea0 0000aaaad6b5e2e0 0000fffff2474e80
[   37.329078] 7fc0: 0000ffffa7c4b1cc 0000000000000000 fffffffffee1dead 000000000000008e
[   37.336997] 7fe0: 0000000000000000 0000000000000000 9ce839cffee77eab fafdbf9f7ed57f2f
[   37.344911] Call trace:
[   37.347437] Exception stack(0xffff800902067b20 to 0xffff800902067c50)
[   37.353970] 7b20: ffff000008e5d4c8 0001000000000000 0000000080f82000 0000000000000000
[   37.361883] 7b40: ffff800902067b60 ffff000008e17000 ffff000008f44c68 00000001081081b4
[   37.369802] 7b60: ffff800902067bf0 ffff000008108478 0000000000000000 ffff000008c235b0
[   37.377721] 7b80: ffff800902067ce0 0000000000000000 0000000000000000 0000000000000015
[   37.385643] 7ba0: 0000000000000123 000000000000008e ffff000008992000 ffff800902068000
[   37.393557] 7bc0: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
[   37.401477] 7be0: 0000000000000000 ffff000008c97dd8 ffff000008cc6fb0 ffff000008cc6fb8
[   37.409396] 7c00: 6974726174736552 ffff800902067a50 0000000005f5e0ff ffff000008e70000
[   37.417318] 7c20: ffff000008e706c0 ffff000008f42bfd ffff000088f42bef 0000000000000006
[   37.425234] 7c40: 00000000deadbeef 0000ffffa7c27470
[   37.430190] [<          (null)>]           (null)
[   37.434982] [<ffff000008085334>] machine_restart+0x6c/0x70
[   37.440550] [<ffff0000080e2c2c>] kernel_restart+0x6c/0x78
[   37.446030] [<ffff0000080e2ee8>] SyS_reboot+0x130/0x228
[   37.451337] [<ffff0000080830f0>] el0_svc_naked+0x24/0x28
[   37.456737] Code: bad PC value
[   37.459891] ---[ end trace 76e2fc17e050aecd ]---
Signed-off-by: NJulien Grall <julien.grall@arm.com>

--

Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: x86@kernel.org

The x86 code has theoritically a similar issue, altought EFI does not
seem to be the preferred method. I have only built test it on x86.

This should also probably be fixed in stable tree.

    Changes in v2:
        - Implement xen_efi_reset_system using xen_reboot
        - Move xen_efi_reset_system in drivers/xen/efi.c
Signed-off-by: NJuergen Gross <jgross@suse.com>

The helper xen_reboot will be called by the EFI code in a later patch.

Note that the ARM version does not yet exist and will be added in a
later patch too.
Signed-off-by: NJulien Grall <julien.grall@arm.com>
Signed-off-by: NJuergen Gross <jgross@suse.com>

Recent code rework that split handling ov PV, HVM and PVH guests into
separate files missed calling xen_smp_intr_init_pv() on CPU0.

Add this call.
Signed-off-by: NBoris Ostrovsky <boris.ostrovsky@oracle.com>
Reported-by: NSander Eikelenboom <linux@eikelenboom.it>
Signed-off-by: NJuergen Gross <jgross@suse.com>

Recent discussion (http://marc.info/?l=xen-devel&m=149192184523741)
established that commit 72a9b186 ("xen: Remove event channel
notification through Xen PCI platform device") (and thus commit
da72ff5b ("partially revert "xen: Remove event channel
notification through Xen PCI platform device"")) are unnecessary and,
in fact, prevent HVM guests from booting on Xen releases prior to 4.0

Therefore we revert both of those commits.

The summary of that discussion is below:

  Here is the brief summary of the current situation:

  Before the offending commit (72a9b186):

  1) INTx does not work because of the reset_watches path.
  2) The reset_watches path is only taken if you have Xen > 4.0
  3) The Linux Kernel by default will use vector inject if the hypervisor
     support. So even INTx does not work no body running the kernel with
     Xen > 4.0 would notice. Unless he explicitly disabled this feature
     either in the kernel or in Xen (and this can only be disabled by
     modifying the code, not user-supported way to do it).

  After the offending commit (+ partial revert):

  1) INTx is no longer support for HVM (only for PV guests).
  2) Any HVM guest The kernel will not boot on Xen < 4.0 which does
     not have vector injection support. Since the only other mode
     supported is INTx which.

  So based on this summary, I think before commit (72a9b186) we were
  in much better position from a user point of view.
Signed-off-by: NBoris Ostrovsky <boris.ostrovsky@oracle.com>
Reviewed-by: NJuergen Gross <jgross@suse.com>
Signed-off-by: NJuergen Gross <jgross@suse.com>

e820 map is updated with information from the zeropage (i.e. pvh_bootparams)
by default_machine_specific_memory_setup(). With the way things are done
now,  we end up with a duplicated e820 map.
Signed-off-by: NBoris Ostrovsky <boris.ostrovsky@oracle.com>
Reviewed-by: NJuergen Gross <jgross@suse.com>
Signed-off-by: NJuergen Gross <jgross@suse.com>

When running as pv domain xen_cpuid() is being used instead of
native_cpuid(). In xen_cpuid() the xsave feature availability is
indicated by special casing the related cpuid leaf.

Instead of delivering fake cpuid values set or clear the cpu
capability bits for xsave instead.
Signed-off-by: NJuergen Gross <jgross@suse.com>
Reviewed-by: NAndrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: NJuergen Gross <jgross@suse.com>

When running as pv domain xen_cpuid() is being used instead of
native_cpuid(). In xen_cpuid() the x2apic feature is indicated as not
being present by special casing the related cpuid leaf.

Instead of delivering fake cpuid values clear the cpu capability bit
for x2apic instead.
Signed-off-by: NJuergen Gross <jgross@suse.com>
Reviewed-by: NBoris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: NJuergen Gross <jgross@suse.com>

When running as pv domain xen_cpuid() is being used instead of
native_cpuid(). In xen_cpuid() the mwait feature is indicated to be
present or not by special casing the related cpuid leaf.

Instead of delivering fake cpuid values use the cpu capability bit
for mwait instead.
Signed-off-by: NJuergen Gross <jgross@suse.com>
Reviewed-by: NBoris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: NJuergen Gross <jgross@suse.com>

When running as pv domain xen_cpuid() is being used instead of
native_cpuid(). In xen_cpuid() the acpi feature is indicated as not
being present by special casing the related cpuid leaf in case we
are not the initial domain.

Instead of delivering fake cpuid values clear the cpu capability bit
for acpi instead.
Signed-off-by: NJuergen Gross <jgross@suse.com>
Reviewed-by: NBoris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: NJuergen Gross <jgross@suse.com>

When running as pv domain xen_cpuid() is being used instead of
native_cpuid(). In xen_cpuid() the acc feature (thermal monitoring)
is indicated as not being present by special casing the related
cpuid leaf.

Instead of delivering fake cpuid values clear the cpu capability bit
for acc instead.
Signed-off-by: NJuergen Gross <jgross@suse.com>
Reviewed-by: NBoris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: NJuergen Gross <jgross@suse.com>

When running as pv domain xen_cpuid() is being used instead of
native_cpuid(). In xen_cpuid() the mtrr feature is indicated as not
being present by special casing the related cpuid leaf.

Instead of delivering fake cpuid values clear the cpu capability bit
for mtrr instead.
Signed-off-by: NJuergen Gross <jgross@suse.com>
Reviewed-by: NBoris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: NJuergen Gross <jgross@suse.com>

When running as pv domain xen_cpuid() is being used instead of
native_cpuid(). In xen_cpuid() the aperf/mperf feature is indicated
as not being present by special casing the related cpuid leaf.

Instead of delivering fake cpuid values clear the cpu capability bit
for aperf/mperf instead.
Signed-off-by: NJuergen Gross <jgross@suse.com>
Reviewed-by: NBoris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: NJuergen Gross <jgross@suse.com>

Xen doesn't support DCA (direct cache access) for pv domains. Clear
the corresponding capability indicator.
Signed-off-by: NJuergen Gross <jgross@suse.com>
Reviewed-by: NBoris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: NJuergen Gross <jgross@suse.com>

There is no need to set the same capabilities for each cpu
individually. This can easily be done for all cpus when starting the
kernel.
Signed-off-by: NJuergen Gross <jgross@suse.com>
Reviewed-by: NBoris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: NJuergen Gross <jgross@suse.com>

For kdump to work correctly it needs the physical address of
vmcoreinfo_note. When running as dom0 this means the virtual address
has to be translated to the related machine address.

paddr_vmcoreinfo_note() is meant to do the translation via
__pa_symbol() only, but being attributed "weak" it can be replaced
easily in Xen case.
Signed-off-by: NJuergen Gross <jgross@suse.com>
Tested-by: NPetr Tesarik <ptesarik@suse.com>
Reviewed-by: NBoris Ostrovsky <boris.ostrovsky@oracle.com>
Reviewed-by: NDaniel Kiper <daniel.kiper@oracle.com>
Signed-off-by: NJuergen Gross <jgross@suse.com>

xen_call_function_interrupt() isn't used in smp_pv.c. Remove it.
Signed-off-by: NJuergen Gross <jgross@suse.com>

After code split between PV and HVM some functions in xen_smp_ops have
xen_pv_ prefix and some only xen_ which makes them look like they're
common for both PV and HVM while they're not. Rename all the rest to
have xen_pv_ prefix.
Signed-off-by: NVitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: NJuergen Gross <jgross@suse.com>
Signed-off-by: NJuergen Gross <jgross@suse.com>