similar to: [PATCH 0/3] GDT virtualization performance

PnP BIOS for x86 is part of drivers, so I missed it in the initial GDT page alignment patch. Kudos to Andrew for fixing that. Unfortunately, fixing the build introduced a kernel panic when trying to setup the as of yet unallocated GDTs for the APs. This fixes the problem by setting only the BSP's GDT, then copying the PnP segments back to the cpu_gdt_table template. Signed-off-by: Zachary

PnP BIOS for x86 is part of drivers, so I missed it in the initial GDT page alignment patch. Kudos to Andrew for fixing that. Unfortunately, fixing the build introduced a kernel panic when trying to setup the as of yet unallocated GDTs for the APs. This fixes the problem by setting only the BSP's GDT, then copying the PnP segments back to the cpu_gdt_table template. Signed-off-by: Zachary

Patches to clean up descriptor access in Linux to make it friendly to virtualization environments. The basic problem is that the GDT must be write protected, which causes spurious overhead when the GDT lies on the same page as other data. This problem exists both for VMware and Xen; Xen actually requires page isolation, so we have implemented the most general and compatible solution. While

Patches to clean up descriptor access in Linux to make it friendly to virtualization environments. The basic problem is that the GDT must be write protected, which causes spurious overhead when the GDT lies on the same page as other data. This problem exists both for VMware and Xen; Xen actually requires page isolation, so we have implemented the most general and compatible solution. While

From: Sylvain Gault <sylvain.gault at gmail.com> The assembly instruction lgdt take a segment limit that is one less than the actual size, so that base+limit points to the last byte. Signed-off-by: Sylvain Gault <sylvain.gault at gmail.com> --- efi/main.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/efi/main.c b/efi/main.c index 94878f9..bdf9353 100644

Make GDT page aligned and page padded to support running inside of a hypervisor. This prevents false sharing of the GDT page with other hot data, which is not allowed in Xen, and causes performance problems in VMware. Rather than go back to the old method of statically allocating the GDT (which wastes unneded space for non-present CPUs), the GDT for APs is allocated dynamically. Signed-off-by:

Make GDT page aligned and page padded to support running inside of a hypervisor. This prevents false sharing of the GDT page with other hot data, which is not allowed in Xen, and causes performance problems in VMware. Rather than go back to the old method of statically allocating the GDT (which wastes unneded space for non-present CPUs), the GDT for APs is allocated dynamically. Signed-off-by:

Hi Andrew, This patch series adds to the end of the existing i386-gdt-cleanups patches: allow-per-cpu-variables-to-be-page-aligned.patch i386-gdt-cleanups-use-per-cpu-variables-for-gdt-pda.patch i386-gdt-cleanups-use-per-cpu-gdt-immediately-upon-boot.patch i386-gdt-cleanups-use-per-cpu-gdt-immediately-upon-boot-fix.patch i386-gdt-cleanups-clean-up-cpu_init.patch

Hi Andrew, This patch series adds to the end of the existing i386-gdt-cleanups patches: allow-per-cpu-variables-to-be-page-aligned.patch i386-gdt-cleanups-use-per-cpu-variables-for-gdt-pda.patch i386-gdt-cleanups-use-per-cpu-gdt-immediately-upon-boot.patch i386-gdt-cleanups-use-per-cpu-gdt-immediately-upon-boot-fix.patch i386-gdt-cleanups-clean-up-cpu_init.patch

Hi all, Testing would be appreciated (esp. Ron?): I'd like to push this as soon as possible into 2.6.23. I thought of it while pondering kvm-lite, and then proved it was a problem... == If a Guest makes hypercall which sets a GDT entry to not present, we currently set any segment registers using that GDT entry to 0. Unfortunately, this is not sufficient: there are other ways of altering

Hi all, Testing would be appreciated (esp. Ron?): I'd like to push this as soon as possible into 2.6.23. I thought of it while pondering kvm-lite, and then proved it was a problem... == If a Guest makes hypercall which sets a GDT entry to not present, we currently set any segment registers using that GDT entry to 0. Unfortunately, this is not sufficient: there are other ways of altering

Add an accessor function for getting the per-CPU gdt. Callee must already have the CPU. Patch-base: 2.6.13-rc5-mm1 Patch-keys: i386 desc xen Signed-off-by: Zachary Amsden <zach@vmware.com> Index: linux-2.6.13/include/asm-i386/desc.h =================================================================== --- linux-2.6.13.orig/include/asm-i386/desc.h 2005-08-09 20:17:21.000000000 -0700 +++

Add an accessor function for getting the per-CPU gdt. Callee must already have the CPU. Patch-base: 2.6.13-rc5-mm1 Patch-keys: i386 desc xen Signed-off-by: Zachary Amsden <zach@vmware.com> Index: linux-2.6.13/include/asm-i386/desc.h =================================================================== --- linux-2.6.13.orig/include/asm-i386/desc.h 2005-08-09 20:17:21.000000000 -0700 +++

On Tue, Feb 11, 2020 at 5:53 AM Joerg Roedel <joro at 8bytes.org> wrote: > > From: Joerg Roedel <jroedel at suse.de> > > Handling exceptions during boot requires a working GDT. The kernel GDT > is not yet ready for use, so install a temporary boot GDT. > > Signed-off-by: Joerg Roedel <jroedel at suse.de> > --- > arch/x86/kernel/head_64.S | 26

On Tue, Apr 28, 2020 at 05:16:22PM +0200, Joerg Roedel wrote: > From: Joerg Roedel <jroedel at suse.de> > > When the pre-decompression code loads its first GDT in startup_64, it is > still running on the CS value of the previous GDT. In the case of SEV-ES > this is the EFI GDT. > > To make exception handling work (especially IRET) the CPU needs to > switch to a CS

On Tue, Apr 28, 2020 at 05:16:41PM +0200, Joerg Roedel wrote: > @@ -480,6 +500,22 @@ SYM_DATA_LOCAL(early_gdt_descr_base, .quad INIT_PER_CPU_VAR(gdt_page)) > SYM_DATA(phys_base, .quad 0x0) > EXPORT_SYMBOL(phys_base) > > +/* Boot GDT used when kernel addresses are not mapped yet */ > +SYM_DATA_LOCAL(boot_gdt_descr, .word boot_gdt_end - boot_gdt) >

On Tue, Apr 28, 2020 at 05:16:41PM +0200, Joerg Roedel wrote: > @@ -480,6 +500,22 @@ SYM_DATA_LOCAL(early_gdt_descr_base, .quad INIT_PER_CPU_VAR(gdt_page)) > SYM_DATA(phys_base, .quad 0x0) > EXPORT_SYMBOL(phys_base) > > +/* Boot GDT used when kernel addresses are not mapped yet */ > +SYM_DATA_LOCAL(boot_gdt_descr, .word boot_gdt_end - boot_gdt) >

Hi, I've installed a few Fedora Core 4 and Fedora Core 5 recently, and found that the new ext3 file systems created with new mkfs.ext3(1.38+) has one more field than EXT3 created with old mkfs.ext3(1.34-), even the latter's dir_index feature was turned on and file systems were upgraded with "e2fsck -y -f -D" command. I have three questions thereafter: 1) what does the

On Mon, Sep 07, 2020 at 03:16:08PM +0200, Joerg Roedel wrote: > From: Joerg Roedel <jroedel at suse.de> > > The IDT on 64bit contains vectors which use paranoid_entry() and/or IST > stacks. To make these vectors work the TSS and the getcpu GDT entry need > to be set up before the IDT is loaded. > > Signed-off-by: Joerg Roedel <jroedel at suse.de> > --- >

As suggested by Andi Kleen, don't allocate a GDT page if there is already one present. Needed for CPU hotplug. Signed-off-by: Zachary Amsden <zach@vmware.com> Index: linux-2.6.14-rc1/arch/i386/kernel/smpboot.c =================================================================== --- linux-2.6.14-rc1.orig/arch/i386/kernel/smpboot.c 2005-09-20 20:38:22.000000000 -0700 +++