* [PATCH 00/13] x86/paravirt: Make pv ops code generation more closely match reality
@ 2017-10-04 15:58 Josh Poimboeuf
0 siblings, 0 replies; 5+ messages in thread
From: Josh Poimboeuf @ 2017-10-04 15:58 UTC (permalink / raw)
To: x86
Cc: Juergen Gross, Rusty Russell, xen-devel, Peter Zijlstra,
Jiri Slaby, Boris Ostrovsky, Mike Galbraith, linux-kernel,
Sasha Levin, Chris Wright, Thomas Gleixner, Andy Lutomirski,
H. Peter Anvin, Borislav Petkov, live-patching, Alok Kataria,
virtualization, Linus Torvalds, Ingo Molnar
This changes the pv ops code generation to more closely match reality.
For example, instead of:
callq *0xffffffff81e3a400 (pv_irq_ops.save_fl)
vmlinux will now show:
pushfq
pop %rax
nop
nop
nop
nop
nop
which is what the runtime version of the code will show in most cases.
This idea was suggested by Andy Lutomirski.
The benefits are:
- For the most common runtime cases (everything except Xen and vSMP),
vmlinux disassembly now matches what the actual runtime code looks
like. This improves debuggability and kernel developer sanity (a
precious resource).
- It fixes a KASAN warning in the ORC unwinder due to objtool not
understanding the .parainstructions stuff.
- It's hopefully a first step in simplifying paravirt patching by
getting rid of .parainstructions, pv ops, and apply_paravirt()
completely. (I think Xen can be changed to set CPU feature bits to
specify which ops it needs during early boot, then those ops can be
patched in using early alternatives.)
For more details, see the commit log in patch 11/13.
Josh Poimboeuf (13):
x86/paravirt: remove wbinvd() paravirt interface
x86/paravirt: Fix output constraint macro names
x86/paravirt: Convert native patch assembly code strings to macros
x86/paravirt: Convert DEF_NATIVE macro to GCC extended asm syntax
x86/paravirt: Move paravirt asm macros to paravirt-asm.h
x86/paravirt: Clean up paravirt-asm.h
x86/paravirt: Simplify ____PVOP_CALL()
x86/paravirt: Clean up paravirt_types.h
x86/asm: Convert ALTERNATIVE*() assembler macros to preprocessor
macros
x86/alternative: Support indirect call replacement
x86/paravirt: Add paravirt alternatives infrastructure
objtool: Add support for new .pv_altinstructions section
x86/paravirt: Convert natively patched pv ops to use paravirt
alternatives
arch/x86/entry/entry_32.S | 13 +-
arch/x86/entry/entry_64.S | 12 +-
arch/x86/entry/entry_64_compat.S | 9 +-
arch/x86/entry/vdso/vdso32/system_call.S | 10 +-
arch/x86/include/asm/alternative-asm.h | 71 ++++-----
arch/x86/include/asm/alternative.h | 12 +-
arch/x86/include/asm/cpufeatures.h | 1 +
arch/x86/include/asm/paravirt-asm.h | 142 ++++++++++++++++++
arch/x86/include/asm/paravirt.h | 174 ++++------------------
arch/x86/include/asm/paravirt_types.h | 243 ++++++++++++++++++++-----------
arch/x86/include/asm/smap.h | 4 +-
arch/x86/include/asm/special_insns.h | 31 +++-
arch/x86/kernel/alternative.c | 35 ++++-
arch/x86/kernel/cpu/hypervisor.c | 2 +
arch/x86/kernel/head_64.S | 2 +-
arch/x86/kernel/module.c | 11 +-
arch/x86/kernel/paravirt.c | 1 -
arch/x86/kernel/paravirt_patch_32.c | 21 +--
arch/x86/kernel/paravirt_patch_64.c | 31 ++--
arch/x86/kernel/vmlinux.lds.S | 6 +
arch/x86/lib/copy_page_64.S | 2 +-
arch/x86/lib/memcpy_64.S | 4 +-
arch/x86/lib/memmove_64.S | 3 +-
arch/x86/lib/memset_64.S | 4 +-
arch/x86/xen/enlighten_pv.c | 3 +-
tools/objtool/special.c | 10 ++
26 files changed, 516 insertions(+), 341 deletions(-)
create mode 100644 arch/x86/include/asm/paravirt-asm.h
--
2.13.6
_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xen.org
https://lists.xen.org/xen-devel
^ permalink raw reply [flat|nested] 5+ messages in thread* [PATCH 00/13] x86/paravirt: Make pv ops code generation more closely match reality
@ 2017-10-04 15:58 Josh Poimboeuf
2017-10-06 7:35 ` [Xen-devel] " Vitaly Kuznetsov
2017-10-06 7:35 ` Vitaly Kuznetsov
0 siblings, 2 replies; 5+ messages in thread
From: Josh Poimboeuf @ 2017-10-04 15:58 UTC (permalink / raw)
To: x86
Cc: linux-kernel, Juergen Gross, Andy Lutomirski, Linus Torvalds,
Sasha Levin, live-patching, Jiri Slaby, Ingo Molnar,
H. Peter Anvin, Peter Zijlstra, Mike Galbraith, Chris Wright,
Alok Kataria, Rusty Russell, virtualization, Boris Ostrovsky,
xen-devel, Thomas Gleixner, Borislav Petkov
This changes the pv ops code generation to more closely match reality.
For example, instead of:
callq *0xffffffff81e3a400 (pv_irq_ops.save_fl)
vmlinux will now show:
pushfq
pop %rax
nop
nop
nop
nop
nop
which is what the runtime version of the code will show in most cases.
This idea was suggested by Andy Lutomirski.
The benefits are:
- For the most common runtime cases (everything except Xen and vSMP),
vmlinux disassembly now matches what the actual runtime code looks
like. This improves debuggability and kernel developer sanity (a
precious resource).
- It fixes a KASAN warning in the ORC unwinder due to objtool not
understanding the .parainstructions stuff.
- It's hopefully a first step in simplifying paravirt patching by
getting rid of .parainstructions, pv ops, and apply_paravirt()
completely. (I think Xen can be changed to set CPU feature bits to
specify which ops it needs during early boot, then those ops can be
patched in using early alternatives.)
For more details, see the commit log in patch 11/13.
Josh Poimboeuf (13):
x86/paravirt: remove wbinvd() paravirt interface
x86/paravirt: Fix output constraint macro names
x86/paravirt: Convert native patch assembly code strings to macros
x86/paravirt: Convert DEF_NATIVE macro to GCC extended asm syntax
x86/paravirt: Move paravirt asm macros to paravirt-asm.h
x86/paravirt: Clean up paravirt-asm.h
x86/paravirt: Simplify ____PVOP_CALL()
x86/paravirt: Clean up paravirt_types.h
x86/asm: Convert ALTERNATIVE*() assembler macros to preprocessor
macros
x86/alternative: Support indirect call replacement
x86/paravirt: Add paravirt alternatives infrastructure
objtool: Add support for new .pv_altinstructions section
x86/paravirt: Convert natively patched pv ops to use paravirt
alternatives
arch/x86/entry/entry_32.S | 13 +-
arch/x86/entry/entry_64.S | 12 +-
arch/x86/entry/entry_64_compat.S | 9 +-
arch/x86/entry/vdso/vdso32/system_call.S | 10 +-
arch/x86/include/asm/alternative-asm.h | 71 ++++-----
arch/x86/include/asm/alternative.h | 12 +-
arch/x86/include/asm/cpufeatures.h | 1 +
arch/x86/include/asm/paravirt-asm.h | 142 ++++++++++++++++++
arch/x86/include/asm/paravirt.h | 174 ++++------------------
arch/x86/include/asm/paravirt_types.h | 243 ++++++++++++++++++++-----------
arch/x86/include/asm/smap.h | 4 +-
arch/x86/include/asm/special_insns.h | 31 +++-
arch/x86/kernel/alternative.c | 35 ++++-
arch/x86/kernel/cpu/hypervisor.c | 2 +
arch/x86/kernel/head_64.S | 2 +-
arch/x86/kernel/module.c | 11 +-
arch/x86/kernel/paravirt.c | 1 -
arch/x86/kernel/paravirt_patch_32.c | 21 +--
arch/x86/kernel/paravirt_patch_64.c | 31 ++--
arch/x86/kernel/vmlinux.lds.S | 6 +
arch/x86/lib/copy_page_64.S | 2 +-
arch/x86/lib/memcpy_64.S | 4 +-
arch/x86/lib/memmove_64.S | 3 +-
arch/x86/lib/memset_64.S | 4 +-
arch/x86/xen/enlighten_pv.c | 3 +-
tools/objtool/special.c | 10 ++
26 files changed, 516 insertions(+), 341 deletions(-)
create mode 100644 arch/x86/include/asm/paravirt-asm.h
--
2.13.6
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [Xen-devel] [PATCH 00/13] x86/paravirt: Make pv ops code generation more closely match reality
2017-10-04 15:58 Josh Poimboeuf
@ 2017-10-06 7:35 ` Vitaly Kuznetsov
2017-10-06 14:36 ` Josh Poimboeuf
2017-10-06 7:35 ` Vitaly Kuznetsov
1 sibling, 1 reply; 5+ messages in thread
From: Vitaly Kuznetsov @ 2017-10-06 7:35 UTC (permalink / raw)
To: Josh Poimboeuf
Cc: x86, Juergen Gross, Rusty Russell, xen-devel, Peter Zijlstra,
Jiri Slaby, Boris Ostrovsky, Mike Galbraith, linux-kernel,
Sasha Levin, Chris Wright, Thomas Gleixner, Andy Lutomirski,
H. Peter Anvin, Borislav Petkov, live-patching, Alok Kataria,
virtualization, Linus Torvalds, Ingo Molnar
Josh Poimboeuf <jpoimboe@redhat.com> writes:
> - For the most common runtime cases (everything except Xen and vSMP),
> vmlinux disassembly now matches what the actual runtime code looks
> like. This improves debuggability and kernel developer sanity (a
> precious resource).
>
> ...
>
> - It's hopefully a first step in simplifying paravirt patching by
> getting rid of .parainstructions, pv ops, and apply_paravirt()
> completely. (I think Xen can be changed to set CPU feature bits to
> specify which ops it needs during early boot, then those ops can be
> patched in using early alternatives.)
JFYI starting 4.14 Xen PV is not the only user of pv_mmu_ops, Hyper-V
uses it for TLB shootdown now.
--
Vitaly
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH 00/13] x86/paravirt: Make pv ops code generation more closely match reality
2017-10-06 7:35 ` [Xen-devel] " Vitaly Kuznetsov
@ 2017-10-06 14:36 ` Josh Poimboeuf
0 siblings, 0 replies; 5+ messages in thread
From: Josh Poimboeuf @ 2017-10-06 14:36 UTC (permalink / raw)
To: Vitaly Kuznetsov
Cc: Juergen Gross, x86, H. Peter Anvin, Peter Zijlstra,
Linus Torvalds, Rusty Russell, Alok Kataria, linux-kernel,
Sasha Levin, Chris Wright, live-patching, Ingo Molnar,
Borislav Petkov, Andy Lutomirski, Mike Galbraith, xen-devel,
Boris Ostrovsky, virtualization, Jiri Slaby, Thomas Gleixner
On Fri, Oct 06, 2017 at 09:35:16AM +0200, Vitaly Kuznetsov wrote:
> Josh Poimboeuf <jpoimboe@redhat.com> writes:
>
> > - For the most common runtime cases (everything except Xen and vSMP),
> > vmlinux disassembly now matches what the actual runtime code looks
> > like. This improves debuggability and kernel developer sanity (a
> > precious resource).
> >
> > ...
> >
> > - It's hopefully a first step in simplifying paravirt patching by
> > getting rid of .parainstructions, pv ops, and apply_paravirt()
> > completely. (I think Xen can be changed to set CPU feature bits to
> > specify which ops it needs during early boot, then those ops can be
> > patched in using early alternatives.)
>
> JFYI starting 4.14 Xen PV is not the only user of pv_mmu_ops, Hyper-V
> uses it for TLB shootdown now.
Yeah, I saw that. It should be fine because the pv_alternatives get
patched before the Hyper-V code sets up pv_mmu_ops.
--
Josh
_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xen.org
https://lists.xen.org/xen-devel
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH 00/13] x86/paravirt: Make pv ops code generation more closely match reality
2017-10-04 15:58 Josh Poimboeuf
2017-10-06 7:35 ` [Xen-devel] " Vitaly Kuznetsov
@ 2017-10-06 7:35 ` Vitaly Kuznetsov
1 sibling, 0 replies; 5+ messages in thread
From: Vitaly Kuznetsov @ 2017-10-06 7:35 UTC (permalink / raw)
To: Josh Poimboeuf
Cc: Juergen Gross, x86, H. Peter Anvin, Peter Zijlstra,
Linus Torvalds, Rusty Russell, Alok Kataria, linux-kernel,
Sasha Levin, Chris Wright, live-patching, Ingo Molnar,
Borislav Petkov, Andy Lutomirski, Mike Galbraith, xen-devel,
Boris Ostrovsky, virtualization, Jiri Slaby, Thomas Gleixner
Josh Poimboeuf <jpoimboe@redhat.com> writes:
> - For the most common runtime cases (everything except Xen and vSMP),
> vmlinux disassembly now matches what the actual runtime code looks
> like. This improves debuggability and kernel developer sanity (a
> precious resource).
>
> ...
>
> - It's hopefully a first step in simplifying paravirt patching by
> getting rid of .parainstructions, pv ops, and apply_paravirt()
> completely. (I think Xen can be changed to set CPU feature bits to
> specify which ops it needs during early boot, then those ops can be
> patched in using early alternatives.)
JFYI starting 4.14 Xen PV is not the only user of pv_mmu_ops, Hyper-V
uses it for TLB shootdown now.
--
Vitaly
_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xen.org
https://lists.xen.org/xen-devel
^ permalink raw reply [flat|nested] 5+ messages in thread
* [PATCH 00/13] x86/paravirt: Make pv ops code generation more closely match reality
@ 2017-10-04 15:58 Josh Poimboeuf
0 siblings, 0 replies; 5+ messages in thread
From: Josh Poimboeuf @ 2017-10-04 15:58 UTC (permalink / raw)
To: x86
Cc: Juergen Gross, Rusty Russell, xen-devel, Peter Zijlstra,
Jiri Slaby, Boris Ostrovsky, Mike Galbraith, linux-kernel,
Sasha Levin, Chris Wright, Thomas Gleixner, Andy Lutomirski,
H. Peter Anvin, Borislav Petkov, live-patching, Alok Kataria,
virtualization, Linus Torvalds, Ingo Molnar
This changes the pv ops code generation to more closely match reality.
For example, instead of:
callq *0xffffffff81e3a400 (pv_irq_ops.save_fl)
vmlinux will now show:
pushfq
pop %rax
nop
nop
nop
nop
nop
which is what the runtime version of the code will show in most cases.
This idea was suggested by Andy Lutomirski.
The benefits are:
- For the most common runtime cases (everything except Xen and vSMP),
vmlinux disassembly now matches what the actual runtime code looks
like. This improves debuggability and kernel developer sanity (a
precious resource).
- It fixes a KASAN warning in the ORC unwinder due to objtool not
understanding the .parainstructions stuff.
- It's hopefully a first step in simplifying paravirt patching by
getting rid of .parainstructions, pv ops, and apply_paravirt()
completely. (I think Xen can be changed to set CPU feature bits to
specify which ops it needs during early boot, then those ops can be
patched in using early alternatives.)
For more details, see the commit log in patch 11/13.
Josh Poimboeuf (13):
x86/paravirt: remove wbinvd() paravirt interface
x86/paravirt: Fix output constraint macro names
x86/paravirt: Convert native patch assembly code strings to macros
x86/paravirt: Convert DEF_NATIVE macro to GCC extended asm syntax
x86/paravirt: Move paravirt asm macros to paravirt-asm.h
x86/paravirt: Clean up paravirt-asm.h
x86/paravirt: Simplify ____PVOP_CALL()
x86/paravirt: Clean up paravirt_types.h
x86/asm: Convert ALTERNATIVE*() assembler macros to preprocessor
macros
x86/alternative: Support indirect call replacement
x86/paravirt: Add paravirt alternatives infrastructure
objtool: Add support for new .pv_altinstructions section
x86/paravirt: Convert natively patched pv ops to use paravirt
alternatives
arch/x86/entry/entry_32.S | 13 +-
arch/x86/entry/entry_64.S | 12 +-
arch/x86/entry/entry_64_compat.S | 9 +-
arch/x86/entry/vdso/vdso32/system_call.S | 10 +-
arch/x86/include/asm/alternative-asm.h | 71 ++++-----
arch/x86/include/asm/alternative.h | 12 +-
arch/x86/include/asm/cpufeatures.h | 1 +
arch/x86/include/asm/paravirt-asm.h | 142 ++++++++++++++++++
arch/x86/include/asm/paravirt.h | 174 ++++------------------
arch/x86/include/asm/paravirt_types.h | 243 ++++++++++++++++++++-----------
arch/x86/include/asm/smap.h | 4 +-
arch/x86/include/asm/special_insns.h | 31 +++-
arch/x86/kernel/alternative.c | 35 ++++-
arch/x86/kernel/cpu/hypervisor.c | 2 +
arch/x86/kernel/head_64.S | 2 +-
arch/x86/kernel/module.c | 11 +-
arch/x86/kernel/paravirt.c | 1 -
arch/x86/kernel/paravirt_patch_32.c | 21 +--
arch/x86/kernel/paravirt_patch_64.c | 31 ++--
arch/x86/kernel/vmlinux.lds.S | 6 +
arch/x86/lib/copy_page_64.S | 2 +-
arch/x86/lib/memcpy_64.S | 4 +-
arch/x86/lib/memmove_64.S | 3 +-
arch/x86/lib/memset_64.S | 4 +-
arch/x86/xen/enlighten_pv.c | 3 +-
tools/objtool/special.c | 10 ++
26 files changed, 516 insertions(+), 341 deletions(-)
create mode 100644 arch/x86/include/asm/paravirt-asm.h
--
2.13.6
^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2017-10-06 14:36 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2017-10-04 15:58 [PATCH 00/13] x86/paravirt: Make pv ops code generation more closely match reality Josh Poimboeuf
2017-10-04 15:58 Josh Poimboeuf
2017-10-06 7:35 ` [Xen-devel] " Vitaly Kuznetsov
2017-10-06 14:36 ` Josh Poimboeuf
2017-10-06 7:35 ` Vitaly Kuznetsov
2017-10-04 15:58 Josh Poimboeuf
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