solved and the nightmare is complete, here's the next one: speculating
after RET instructions and leaking privileged information using the now
pretty much classical covert channels.
It is called RETBleed and the mitigation effort and controlling
functionality has been modelled similar to what already existing
mitigations provide.
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Merge tag 'x86_bugs_retbleed' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 retbleed fixes from Borislav Petkov:
"Just when you thought that all the speculation bugs were addressed and
solved and the nightmare is complete, here's the next one: speculating
after RET instructions and leaking privileged information using the
now pretty much classical covert channels.
It is called RETBleed and the mitigation effort and controlling
functionality has been modelled similar to what already existing
mitigations provide"
* tag 'x86_bugs_retbleed' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (54 commits)
x86/speculation: Disable RRSBA behavior
x86/kexec: Disable RET on kexec
x86/bugs: Do not enable IBPB-on-entry when IBPB is not supported
x86/entry: Move PUSH_AND_CLEAR_REGS() back into error_entry
x86/bugs: Add Cannon lake to RETBleed affected CPU list
x86/retbleed: Add fine grained Kconfig knobs
x86/cpu/amd: Enumerate BTC_NO
x86/common: Stamp out the stepping madness
KVM: VMX: Prevent RSB underflow before vmenter
x86/speculation: Fill RSB on vmexit for IBRS
KVM: VMX: Fix IBRS handling after vmexit
KVM: VMX: Prevent guest RSB poisoning attacks with eIBRS
KVM: VMX: Convert launched argument to flags
KVM: VMX: Flatten __vmx_vcpu_run()
objtool: Re-add UNWIND_HINT_{SAVE_RESTORE}
x86/speculation: Remove x86_spec_ctrl_mask
x86/speculation: Use cached host SPEC_CTRL value for guest entry/exit
x86/speculation: Fix SPEC_CTRL write on SMT state change
x86/speculation: Fix firmware entry SPEC_CTRL handling
x86/speculation: Fix RSB filling with CONFIG_RETPOLINE=n
...
Instead of clearing the bss area in assembly code, use the clear_bss()
function.
This requires to pass the start_info address as parameter to
xen_start_kernel() in order to avoid the xen_start_info being zeroed
again.
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Link: https://lore.kernel.org/r/20220630071441.28576-2-jgross@suse.com
Update retpoline validation with the new CONFIG_RETPOLINE requirement of
not having bare naked RET instructions.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
The startup_xen() kernel entry point is referenced by the ".note.Xen"
section, and is the real entry point of the VM. Control transfer is
through IRET, which *could* set NEED_ENDBR, however Xen currently does
no such thing.
Add ANNOTATE_NOENDBR to silence future objtool warnings.
Fixes: ed53a0d971 ("x86/alternative: Use .ibt_endbr_seal to seal indirect calls")
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Link: https://lkml.kernel.org/r/a87bd48b06d11ec4b98122a429e71e489b4e48c3.1650300597.git.jpoimboe@redhat.com
Even though Xen currently doesn't advertise IBT, prepare for when it
will eventually do so and sprinkle the ENDBR dust accordingly.
Even though most of the entry points are IRET like, the CPL0
Hypervisor can set WAIT-FOR-ENDBR and demand ENDBR at these sites.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Link: https://lore.kernel.org/r/20220308154317.873919996@infradead.org
Replace all ret/retq instructions with RET in preparation of making
RET a macro. Since AS is case insensitive it's a big no-op without
RET defined.
find arch/x86/ -name \*.S | while read file
do
sed -i 's/\<ret[q]*\>/RET/' $file
done
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lore.kernel.org/r/20211204134907.905503893@infradead.org
startup_xen is still 32-bit aware, even if no longer needed.
Replace the register macros by the 64-bit register names for making
it more readable.
Signed-off-by: Juergen Gross <jgross@suse.com>
Link: https://lore.kernel.org/r/20211028081221.2475-5-jgross@suse.com
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Because hypercall_page is page-aligned, the assembler inexplicably adds
an unreachable jump from after the end of the previous code to the
beginning of hypercall_page.
That confuses objtool, understandably. It also creates significant text
fragmentation. As a result, much of the object file is wasted text
(nops).
Move hypercall_page to the beginning of the file to both prevent the
text fragmentation and avoid the dead jump instruction.
$ size /tmp/head_64.before.o /tmp/head_64.after.o
text data bss dec hex filename
10924 307252 4096 322272 4eae0 /tmp/head_64.before.o
6823 307252 4096 318171 4dadb /tmp/head_64.after.o
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Juergen Gross <jgross@suse.com>
Link: https://lkml.kernel.org/r/20210820193107.omvshmsqbpxufzkc@treble
The Xen hypercall page is filled with zeros, causing objtool to fall
through all the empty hypercall functions until it reaches a real
function, resulting in a stack state mismatch.
The build-time contents of the hypercall page don't matter because the
page gets rewritten by the hypervisor. Make it more palatable to
objtool by making each hypervisor function a true empty function, with
nops and a return.
Cc: Juergen Gross <jgross@suse.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Link: https://lore.kernel.org/r/0883bde1d7a1fb3b6a4c952bc0200e873752f609.1611263462.git.jpoimboe@redhat.com
Xen is requiring 64-bit machines today and since Xen 4.14 it can be
built without 32-bit PV guest support. There is no need to carry the
burden of 32-bit PV guest support in the kernel any longer, as new
guests can be either HVM or PVH, or they can use a 64 bit kernel.
Remove the 32-bit Xen PV support from the kernel.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Commit 2f62f36e62 ("x86/xen: Make the boot CPU idle task reliable")
introduced a regression for booting 32 bit Xen PV guests: the address
of the initial stack needs to be a virtual one.
Fixes: 2f62f36e62 ("x86/xen: Make the boot CPU idle task reliable")
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Link: https://lore.kernel.org/r/20200409070001.16675-1-jgross@suse.com
Signed-off-by: Juergen Gross <jgross@suse.com>
The unwinder reports the secondary CPU idle tasks' stack on XEN PV as
unreliable, which affects at least live patching.
cpu_initialize_context() sets up the context of the CPU through
VCPUOP_initialise hypercall. After it is woken up, the idle task starts
in cpu_bringup_and_idle() function and its stack starts at the offset
right below pt_regs. The unwinder correctly detects the end of stack
there but it is confused by NULL return address in the last frame.
Introduce a wrapper in assembly, which just calls
cpu_bringup_and_idle(). The return address is thus pushed on the stack
and the wrapper contains the annotation hint for the unwinder regarding
the stack state.
Signed-off-by: Miroslav Benes <mbenes@suse.cz>
Reviewed-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
The unwinder reports the boot CPU idle task's stack on XEN PV as
unreliable, which affects at least live patching. There are two reasons
for this. First, the task does not follow the x86 convention that its
stack starts at the offset right below saved pt_regs. It allows the
unwinder to easily detect the end of the stack and verify it. Second,
startup_xen() function does not store the return address before jumping
to xen_start_kernel() which confuses the unwinder.
Amend both issues by moving the starting point of initial stack in
startup_xen() and storing the return address before the jump, which is
exactly what call instruction does.
Signed-off-by: Miroslav Benes <mbenes@suse.cz>
Reviewed-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Change all assembly code which is marked using END (and not ENDPROC).
Switch all these to the appropriate new annotation SYM_CODE_START and
SYM_CODE_END.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> [xen bits]
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Cao jin <caoj.fnst@cn.fujitsu.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: linux-arch@vger.kernel.org
Cc: Maran Wilson <maran.wilson@oracle.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stefano Stabellini <sstabellini@kernel.org>
Cc: "Steven Rostedt (VMware)" <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: x86-ml <x86@kernel.org>
Cc: xen-devel@lists.xenproject.org
Link: https://lkml.kernel.org/r/20191011115108.12392-24-jslaby@suse.cz
Currently, the IRQ stack is hardcoded as the first page of the percpu
area, and the stack canary lives on the IRQ stack. The former gets in
the way of adding an IRQ stack guard page, and the latter is a potential
weakness in the stack canary mechanism.
Split the IRQ stack into its own private percpu pages.
[ tglx: Make 64 and 32 bit share struct irq_stack ]
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Brijesh Singh <brijesh.singh@amd.com>
Cc: "Chang S. Bae" <chang.seok.bae@intel.com>
Cc: Dominik Brodowski <linux@dominikbrodowski.net>
Cc: Feng Tang <feng.tang@intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jan Beulich <JBeulich@suse.com>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: Jordan Borgner <mail@jordan-borgner.de>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Maran Wilson <maran.wilson@oracle.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Nicolai Stange <nstange@suse.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Pu Wen <puwen@hygon.cn>
Cc: "Rafael Ávila de Espíndola" <rafael@espindo.la>
Cc: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: Stefano Stabellini <sstabellini@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: x86-ml <x86@kernel.org>
Cc: xen-devel@lists.xenproject.org
Link: https://lkml.kernel.org/r/20190414160146.267376656@linutronix.de
Pre-4.17 kernels ignored start_info's rsdp_paddr pointer and instead
relied on finding RSDP in standard location in BIOS RO memory. This
has worked since that's where Xen used to place it.
However, with recent Xen change (commit 4a5733771e6f ("libxl: put RSDP
for PVH guest near 4GB")) it prefers to keep RSDP at a "non-standard"
address. Even though as of commit b17d9d1df3 ("x86/xen: Add pvh
specific rsdp address retrieval function") Linux is able to find RSDP,
for back-compatibility reasons we need to indicate to Xen that we can
handle this, an we do so by setting XENFEAT_linux_rsdp_unrestricted
flag in ELF notes.
(Also take this opportunity and sync features.h header file with Xen)
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Wei Liu <wei.liu2@citrix.com>
When running as Xen pv guest %gs is initialized some time after
C code is started. Depending on stack protector usage this might be
too late, resulting in page faults.
So setup %gs and MSR_GS_BASE in assembly code already.
Cc: stable@vger.kernel.org
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Tested-by: Chris Patterson <cjp256@gmail.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.
By default all files without license information are under the default
license of the kernel, which is GPL version 2.
Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.
This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.
How this work was done:
Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,
Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.
The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.
The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.
Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if <5
lines).
All documentation files were explicitly excluded.
The following heuristics were used to determine which SPDX license
identifiers to apply.
- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.
For non */uapi/* files that summary was:
SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139
and resulted in the first patch in this series.
If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was:
SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930
and resulted in the second patch in this series.
- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:
SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1
and that resulted in the third patch in this series.
- when the two scanners agreed on the detected license(s), that became
the concluded license(s).
- when there was disagreement between the two scanners (one detected a
license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.
- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply (and
which scanner probably needed to revisit its heuristics).
- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.
- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.
In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.
Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights. The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.
Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.
In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.
Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch license
was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
SPDX license was correct
This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.
These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add unwind hint annotations to the xen head code so the ORC unwinder can
read head_64.o.
hypercall_page needs empty annotations at 32-byte intervals to match the
'xen_hypercall_*' ELF functions at those locations.
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Jiri Slaby <jslaby@suse.cz>
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>
Link: http://lkml.kernel.org/r/70ed2eb516fe9266be766d953f93c2571bca88cc.1505764066.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
XEN_ELFNOTE_INIT_P2M has to be 512GB for both 4- and 5-level paging.
(PUD_SIZE * PTRS_PER_PUD) would do this.
Unfortunately, we cannot use P4D_SIZE, which would fit here. With
current headers structure it cannot be used in assembly, if p4d
level is folded.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Dave Hansen <dave.hansen@intel.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/20170716225954.74185-4-kirill.shutemov@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
We are replacing existing PVH guests with new implementation.
We are keeping xen_pvh_domain() macro (for now set to zero) because
when we introduce new PVH implementation later in this series we will
reuse current PVH-specific code (xen_pvh_gnttab_setup()), and that
code is conditioned by 'if (xen_pvh_domain())'. (We will also need
a noop xen_pvh_domain() for !CONFIG_XEN_PVH).
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
ELF spec is unclear about whether .bss must me cleared by the loader.
Currently the domain builder does it when loading the guest but because
it is not (or rather may not be) guaranteed we should zero it out
explicitly.
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Direct Xen to place the initial P->M table outside of the initial
mapping, as otherwise the 1G (implementation) / 2G (theoretical)
restriction on the size of the initial mapping limits the amount
of memory a domain can be handed initially.
As the initial P->M table is copied rather early during boot to
domain private memory and it's initial virtual mapping is dropped,
the easiest way to avoid virtual address conflicts with other
addresses in the kernel is to use a user address area for the
virtual address of the initial P->M table. This allows us to just
throw away the page tables of the initial mapping after the copy
without having to care about address invalidation.
It should be noted that this patch won't enable a pv-domain to USE
more than 512 GB of RAM. It just enables it to be started with a
P->M table covering more memory. This is especially important for
being able to boot a Dom0 on a system with more than 512 GB memory.
Signed-off-by: Juergen Gross <jgross@suse.com>
Based-on-patch-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Konrad Rzeszutek Wilk <Konrad.wilk@oracle.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Instead of manually list each hypercall in arch/x86/xen/xen-head.S
use the auto generated symbol list.
This also corrects the wrong address of xen_hypercall_mca which was
located 32 bytes higher than it should.
Symbol addresses have been verified to match the correct ones via
objdump output.
Based-on-patch-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: David Vrabel <david.vrabel@citrix.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
This fixes two bugs in PVH guests:
- Not setting EFER.NX means the NX bit in page table entries is
ignored on Intel processors and causes reserved bit page faults on
AMD processors.
- After the Xen commit 7645640d6ff1 ("x86/PVH: don't set EFER_SCE for
pvh guest") PVH guests are required to set EFER.SCE to enable the
SYSCALL instruction.
Secondary VCPUs are started with pagetables with the NX bit set so
EFER.NX must be set before using any stack or data segment.
xen_pvh_cpu_early_init() is the new secondary VCPU entry point that
sets EFER before jumping to cpu_bringup_and_idle().
Signed-off-by: Mukesh Rathor <mukesh.rathor@oracle.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Size restrictions native kernels wouldn't have resulted from the initrd
getting mapped into the initial mapping. The kernel doesn't really need
the initrd to be mapped, so use infrastructure available in Xen to avoid
the mapping and hence the restriction.
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
PVH allows PV linux guest to utilize hardware extended capabilities,
such as running MMU updates in a HVM container.
The Xen side defines PVH as (from docs/misc/pvh-readme.txt,
with modifications):
"* the guest uses auto translate:
- p2m is managed by Xen
- pagetables are owned by the guest
- mmu_update hypercall not available
* it uses event callback and not vlapic emulation,
* IDT is native, so set_trap_table hcall is also N/A for a PVH guest.
For a full list of hcalls supported for PVH, see pvh_hypercall64_table
in arch/x86/hvm/hvm.c in xen. From the ABI prespective, it's mostly a
PV guest with auto translate, although it does use hvm_op for setting
callback vector."
Use .ascii and .asciz to define xen feature string. Note, the PVH
string must be in a single line (not multiple lines with \) to keep the
assembler from putting null char after each string before \.
This patch allows it to be configured and enabled.
We also use introduce the 'XEN_ELFNOTE_SUPPORTED_FEATURES' ELF note to
tell the hypervisor that 'hvm_callback_vector' is what the kernel
needs. We can not put it in 'XEN_ELFNOTE_FEATURES' as older hypervisor
parse fields they don't understand as errors and refuse to load
the kernel. This work-around fixes the problem.
Signed-off-by: Mukesh Rathor <mukesh.rathor@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
This allows us in perf to have this:
99.67% [kernel] [k] xen_hypercall_sched_op
0.11% [kernel] [k] xen_hypercall_xen_version
instead of the borring ever-encompassing:
99.13% [kernel] [k] hypercall_page
[v2: Use a macro to define the name and skip]
[v3: Use balign per Jan's suggestion]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
PAGE_SIZE_asm, PAGE_SHIFT_asm, THREAD_SIZE_asm can be safely removed from
asm-offsets.c, and be replaced by their non-'_asm' counterparts in the code
that uses them, since the _AC macro defined in include/linux/const.h makes
PAGE_SIZE/PAGE_SHIFT/THREAD_SIZE work with as.
Signed-off-by: Stratos Psomadakis <psomas@cslab.ece.ntua.gr>
LKML-Reference: <1298666774-17646-2-git-send-email-psomas@cslab.ece.ntua.gr>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
In general, the only definitions that assembly files can use
are in _types.S headers (where available), so convert them.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Add the Xen entrypoint and ELF notes to head_64.S. Adapts xen-head.S
to compile either 32-bit or 64-bit.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Stephen Tweedie <sct@redhat.com>
Cc: Eduardo Habkost <ehabkost@redhat.com>
Cc: Mark McLoughlin <markmc@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Because NX is now enforced properly, we must put the hypercall page
into the .text segment so that it is executable.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Stable Kernel <stable@kernel.org>
Cc: the arch/x86 maintainers <x86@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Define recently added XEN_ELFNOTEs, and use them appropriately.
Most significantly, this enables domain checkpointing (xm save -c).
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Non-PAE operation has been deprecated in Xen for a while, and is
rarely tested or used. xen-unstable has now officially dropped
non-PAE support. Since Xen/pvops' non-PAE support has also been
broken for a while, we may as well completely drop it altogether.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
additional section for .init.text appending a number.
A side effect of this was a section mismatch warning because modpost did
not recognize a .init.text section named .init.text.1: WARNING:
vmlinux.o(.text.head+0x247): Section mismatch: reference to
.init.text.1:start_kernel (between 'is386' and 'check_x87')
Fix this by hardcoding the "ax" in the pushsection. Thanks to Torlaf for
reporting this.
Alan Modra provided the hint that made me able to locate the root cause of
this warning. And Mike Frysinger told me how to properly fix it using
__INIT/__FINIT.
Fix following Section mismatch warning in addition:
WARNING: vmlinux.o(.text+0x14c8): Section mismatch: reference to .init.data:vsyscall_int80_start (between 'fiddle_vdso' and 'xen_setup_features')
fiddle_vdso was only used from a __init function - so declare it __init.
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Cc: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: Chris Wright <chrisw@sous-sol.org>
Cc: WANG Cong <xiyou.wangcong@gmail.com>
Cc: Toralf Förster <toralf.foerster@gmx.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Linus Torvalds
Juergen Gross
Peter Zijlstra
Josh Poimboeuf
Miroslav Benes
Jiri Slaby
Andy Lutomirski
Boris Ostrovsky
Ingo Molnar
Greg Kroah-Hartman
Kirill A. Shutemov
Vitaly Kuznetsov
Adam Buchbinder
Mukesh Rathor
Konrad Rzeszutek Wilk
Stratos Psomadakis
Jeremy Fitzhardinge
Jeremy Fitzhardinge
Sam Ravnborg
Thomas Gleixner