similar to: [PATCH 0/3] Fix and cleanup for 32-bit PV sysexit

The first patch fixes Xen PV regression introduced by 32-bit rewrite. Unlike the earlier version it uses ALTERNATIVE instruction and avoids using xen_sysexit (and sysret32 in compat mode) pv ops, as suggested by Andy. As result of this patch irq_enable_sysexit and usergs_sysret32 pv ops are not used anymore by anyone and so can be removed. v2: * patch both TEST and JZ intructions with a

The first patch fixes Xen PV regression introduced by 32-bit rewrite. Unlike the earlier version it uses ALTERNATIVE instruction and avoids using xen_sysexit (and sysret32 in compat mode) pv ops, as suggested by Andy. As result of this patch irq_enable_sysexit and usergs_sysret32 pv ops are not used anymore by anyone and so can be removed. v2: * patch both TEST and JZ intructions with a

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

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

On Wed, Nov 18, 2015 at 12:06 PM, Boris Ostrovsky <boris.ostrovsky at oracle.com> wrote: > After 32-bit syscall rewrite, and specifically after commit 5f310f739b4c > ("x86/entry/32: Re-implement SYSENTER using the new C path"), the stack > frame that is passed to xen_sysexit is no longer a "standard" one (i.e. > it's not pt_regs). > > Since we end up

On Wed, Nov 18, 2015 at 12:06 PM, Boris Ostrovsky <boris.ostrovsky at oracle.com> wrote: > After 32-bit syscall rewrite, and specifically after commit 5f310f739b4c > ("x86/entry/32: Re-implement SYSENTER using the new C path"), the stack > frame that is passed to xen_sysexit is no longer a "standard" one (i.e. > it's not pt_regs). > > Since we end up

Today paravirtualization is a all-or-nothing game: either a kernel is compiled with no paravirtualization support at all, or it is supporting paravirtualized environments like Xen pv-guests or lguest additionally to some paravirtualized tuning for KVM, Hyperv, VMWare or Xen HVM-guests. As support of pv-guests requires quite intrusive pv-hooks (e.g. all access functions to page table entries,

Today paravirtualization is a all-or-nothing game: either a kernel is compiled with no paravirtualization support at all, or it is supporting paravirtualized environments like Xen pv-guests or lguest additionally to some paravirtualized tuning for KVM, Hyperv, VMWare or Xen HVM-guests. As support of pv-guests requires quite intrusive pv-hooks (e.g. all access functions to page table entries,

This series removes some no longer needed stuff from paravirt infrastructure and puts large quantities of paravirt ops under a new config option PARAVIRT_XXL which is selected by XEN_PV only. A pvops kernel without XEN_PV being configured is about 2.5% smaller with this series applied. tip commit 5800dc5c19f34e6e03b5adab1282535cb102fafd ("x86/paravirt: Fix spectre-v2 mitigations for

This series removes some no longer needed stuff from paravirt infrastructure and puts large quantities of paravirt ops under a new config option PARAVIRT_XXL which is selected by XEN_PV only. A pvops kernel without XEN_PV being configured is about 2.5% smaller with this series applied. tip commit 5800dc5c19f34e6e03b5adab1282535cb102fafd ("x86/paravirt: Fix spectre-v2 mitigations for

Hi folks, Here is the result of the latest work on the pvops front, after the x86 arch merge. From the functionality point of view, almost nothing was changed, except for proper vsmp support - which was discussed, but not implemented before - and the introduction of smp_ops in x86_64, which eased the merging of the smp header. Speaking of the merge, a significant part (although not majority) of

Hi folks, Here is the result of the latest work on the pvops front, after the x86 arch merge. From the functionality point of view, almost nothing was changed, except for proper vsmp support - which was discussed, but not implemented before - and the introduction of smp_ops in x86_64, which eased the merging of the smp header. Speaking of the merge, a significant part (although not majority) of

Hi folks, With this series, the bulk of the work of pvops64 is done. Here, I integrate most of the paravirt.c and paravirt.h files, making them applicable to both architectures. CONFIG_PARAVIRT is _not_ present yet. Basically, this code is missing page table integration (patches currently being worked on by Jeremy). Enjoy

Hi folks, With this series, the bulk of the work of pvops64 is done. Here, I integrate most of the paravirt.c and paravirt.h files, making them applicable to both architectures. CONFIG_PARAVIRT is _not_ present yet. Basically, this code is missing page table integration (patches currently being worked on by Jeremy). Enjoy

On 10/24/2014 04:54 AM, Peter Zijlstra wrote: > On Thu, Oct 16, 2014 at 02:10:38PM -0400, Waiman Long wrote: > >> Since enabling paravirt spinlock will disable unlock function inlining, >> a jump label can be added to the unlock function without adding patch >> sites all over the kernel. > But you don't have to. My patches allowed for the inline to remain, > again

On 10/24/2014 04:54 AM, Peter Zijlstra wrote: > On Thu, Oct 16, 2014 at 02:10:38PM -0400, Waiman Long wrote: > >> Since enabling paravirt spinlock will disable unlock function inlining, >> a jump label can be added to the unlock function without adding patch >> sites all over the kernel. > But you don't have to. My patches allowed for the inline to remain, > again

The long term plan has been to replace Xen PV guests by PVH. The first victim of that plan are now 32-bit PV guests, as those are used only rather seldom these days. Xen on x86 requires 64-bit support and with Grub2 now supporting PVH officially since version 2.04 there is no need to keep 32-bit PV guest support alive in the Linux kernel. Additionally Meltdown mitigation is not available in the

The long term plan has been to replace Xen PV guests by PVH. The first victim of that plan are now 32-bit PV guests, as those are used only rather seldom these days. Xen on x86 requires 64-bit support and with Grub2 now supporting PVH officially since version 2.04 there is no need to keep 32-bit PV guest support alive in the Linux kernel. Additionally Meltdown mitigation is not available in the

On 10/27/2014 02:04 PM, Peter Zijlstra wrote: > On Mon, Oct 27, 2014 at 01:38:20PM -0400, Waiman Long wrote: >> On 10/24/2014 04:54 AM, Peter Zijlstra wrote: >>> On Thu, Oct 16, 2014 at 02:10:38PM -0400, Waiman Long wrote: >>> >>>> Since enabling paravirt spinlock will disable unlock function inlining, >>>> a jump label can be added to the unlock

On 10/27/2014 02:04 PM, Peter Zijlstra wrote: > On Mon, Oct 27, 2014 at 01:38:20PM -0400, Waiman Long wrote: >> On 10/24/2014 04:54 AM, Peter Zijlstra wrote: >>> On Thu, Oct 16, 2014 at 02:10:38PM -0400, Waiman Long wrote: >>> >>>> Since enabling paravirt spinlock will disable unlock function inlining, >>>> a jump label can be added to the unlock