similar to: [PATCH 3/6] i386 virtualization - Make ldt a desc struct

Big cleanup of LDT code. This code has very little type checking and is not frequently used, so I audited the code, added type checking and size optimizations to generate smaller assembly code. I changed the ldt count to be in pages, and converted the char * ldt into a desc_struct. Signed-off-by: Zachary Amsden <zach@vmware.com> Index: linux-2.6.14-zach-work/arch/i386/kernel/ldt.c

Big cleanup of LDT code. This code has very little type checking and is not frequently used, so I audited the code, added type checking and size optimizations to generate smaller assembly code. I changed the ldt count to be in pages, and converted the char * ldt into a desc_struct. Signed-off-by: Zachary Amsden <zach@vmware.com> Index: linux-2.6.14-zach-work/arch/i386/kernel/ldt.c

By moving init_new_context and destroy_context inline into mmu_context.h, we can avoid extra functions calls, which are only needed for the unlikely case that the process context has an LDT to deal with. Now the code in ldt.c is called only when actually dealing with LDT creation or destruction. Careful analysis of alloc_ldt function showed that by using two const parameters, huge amounts of

By moving init_new_context and destroy_context inline into mmu_context.h, we can avoid extra functions calls, which are only needed for the unlikely case that the process context has an LDT to deal with. Now the code in ldt.c is called only when actually dealing with LDT creation or destruction. Careful analysis of alloc_ldt function showed that by using two const parameters, huge amounts of

Add Xen accessors for LDT updates. Todo: Bring back return values from write_ldt_entry. Signed-off-by: Zachary Amsden <zach@vmware.com> Index: linux-2.6.13/arch/i386/kernel/ldt.c =================================================================== --- linux-2.6.13.orig/arch/i386/kernel/ldt.c 2005-08-08 21:13:56.000000000 -0700 +++ linux-2.6.13/arch/i386/kernel/ldt.c 2005-08-08

Add Xen accessors for LDT updates. Todo: Bring back return values from write_ldt_entry. Signed-off-by: Zachary Amsden <zach@vmware.com> Index: linux-2.6.13/arch/i386/kernel/ldt.c =================================================================== --- linux-2.6.13.orig/arch/i386/kernel/ldt.c 2005-08-08 21:13:56.000000000 -0700 +++ linux-2.6.13/arch/i386/kernel/ldt.c 2005-08-08

Add hooks that the hypervisor can use to establish writable and non-writable pages for LDT pages. I made these parallel the page flags as defined in include/linux/page-flags.h, since the flag mechanism is very similar to the hypercall page flagging, and extended easily later to include PT, PD, PDP, GDT, etc. Patch-against: 2.6.13-rc5-mm1 Patch-keys: i386 ldt paravirt xen Signed-off-by: Zachary

Add hooks that the hypervisor can use to establish writable and non-writable pages for LDT pages. I made these parallel the page flags as defined in include/linux/page-flags.h, since the flag mechanism is very similar to the hypercall page flagging, and extended easily later to include PT, PD, PDP, GDT, etc. Patch-against: 2.6.13-rc5-mm1 Patch-keys: i386 ldt paravirt xen Signed-off-by: Zachary

Index: linux-2.6.13/arch/i386/kernel/ldt.c =================================================================== --- linux-2.6.13.orig/arch/i386/kernel/ldt.c 2005-08-08 15:27:26.000000000 -0700 +++ linux-2.6.13/arch/i386/kernel/ldt.c 2005-08-08 21:13:19.000000000 -0700 @@ -18,6 +18,7 @@ #include <asm/system.h> #include <asm/ldt.h> #include <asm/desc.h> +#include

Index: linux-2.6.13/arch/i386/kernel/ldt.c =================================================================== --- linux-2.6.13.orig/arch/i386/kernel/ldt.c 2005-08-08 15:27:26.000000000 -0700 +++ linux-2.6.13/arch/i386/kernel/ldt.c 2005-08-08 21:13:19.000000000 -0700 @@ -18,6 +18,7 @@ #include <asm/system.h> #include <asm/ldt.h> #include <asm/desc.h> +#include

On Fri, 23 Jun 2023 23:14:39 +0200, Julia Lawall <Julia.Lawall at inria.fr> wrote: > Use array_size to protect against multiplication overflows. > > The changes were done using the following Coccinelle semantic patch: > > // <smpl> > @@ > expression E1, E2; > constant C1, C2; > identifier alloc = {vmalloc,vzalloc}; > @@ > > ( >

Each virtio-mem device owns exactly one memory region. It is responsible for adding/removing memory from that memory region on request. When the device driver starts up, the requested amount of memory is queried and then plugged to Linux. On request, further memory can be plugged or unplugged. This patch only implements the plugging part. On x86-64, memory can currently be plugged in 4MB

Big cleanup of LDT code. This code has very little type checking and is not frequently used, so I audited the code, added type checking and size optimizations to generate smaller assembly code. First, just introduce some small definitions that will be used later. Signed-off-by: Zachary Amsden <zach@vmware.com> Index: linux-2.6.14-zach-work/arch/i386/kernel/entry.S

Big cleanup of LDT code. This code has very little type checking and is not frequently used, so I audited the code, added type checking and size optimizations to generate smaller assembly code. First, just introduce some small definitions that will be used later. Signed-off-by: Zachary Amsden <zach@vmware.com> Index: linux-2.6.14-zach-work/arch/i386/kernel/entry.S

1: correct LDT checks 2: add address validity check to guest_map_l1e() 3: use {rd,wr}{fs,gs}base when available 4: check for canonical address before doing page walks Signed-off-by: Jan Beulich <jbeulich@suse.com>

I was also able to get the LDT switching functionality out of the critical path in switch_mm, which reduces the number of function calls, potential TLB misses and code size. Signed-off-by: Zachary Amsden <zach@vmware.com> Index: linux-2.6.14-zach-work/include/asm-i386/desc.h =================================================================== ---

I was also able to get the LDT switching functionality out of the critical path in switch_mm, which reduces the number of function calls, potential TLB misses and code size. Signed-off-by: Zachary Amsden <zach@vmware.com> Index: linux-2.6.14-zach-work/include/asm-i386/desc.h =================================================================== ---

Xen uses lazy pinning of MM structures including the page table root and LDT, which requires hooks at context creation and destruction time to maintain the lazy list. Patch-against: 2.6.13-rc5-mm1 Patch-keys: i386 mmu paravirt xen Signed-off-by: Zachary Amsden <zach@vmware.com> Index: linux-2.6.13/include/asm-i386/mmu_context.h

Xen uses lazy pinning of MM structures including the page table root and LDT, which requires hooks at context creation and destruction time to maintain the lazy list. Patch-against: 2.6.13-rc5-mm1 Patch-keys: i386 mmu paravirt xen Signed-off-by: Zachary Amsden <zach@vmware.com> Index: linux-2.6.13/include/asm-i386/mmu_context.h

Introduce a write acessor for updating the current LDT. This is required for hypervisors like Xen that do not allow LDT pages to be directly written. Testing - here's a fun little LDT test that can be trivially modified to test limits as well. /* * Copyright (c) 2005, Zachary Amsden (zach@vmware.com) * This is licensed under the GPL. */ #include <stdio.h> #include <signal.h>