similar to: [PATCH] Slight cleanups for x86 ring macros (against rc3-mm2)

In-Reply-To: <20060803002518.190834642@xensource.com> On Wed, 02 Aug 2006 17:25:13 -0700, Jeremy Fitzhardinge wrote: > We allow for the fact that the guest kernel may not run in ring 0. > This requires some abstraction in a few places when setting %cs or > checking privilege level (user vs kernel). I made some changes: a. Added some comments about the SEGMENT_IS_*_CODE() macros.

In-Reply-To: <20060803002518.190834642@xensource.com> On Wed, 02 Aug 2006 17:25:13 -0700, Jeremy Fitzhardinge wrote: > We allow for the fact that the guest kernel may not run in ring 0. > This requires some abstraction in a few places when setting %cs or > checking privilege level (user vs kernel). I made some changes: a. Added some comments about the SEGMENT_IS_*_CODE() macros.

Make the Linux kernel able to run at CPL 0, 1, or 2. There are a few limited places where CPL-0 is assumed, and they can be converted very efficiently into a supervisor CPL check instead of a CPL-0 check. This step prepares the kernel for running in direct execution under a hypervisor. Note the user_mode_vm macro used in ptrace.h is very similar to the flag mixing of EFLAGS and CS used to test

Make the Linux kernel able to run at CPL 0, 1, or 2. There are a few limited places where CPL-0 is assumed, and they can be converted very efficiently into a supervisor CPL check instead of a CPL-0 check. This step prepares the kernel for running in direct execution under a hypervisor. Note the user_mode_vm macro used in ptrace.h is very similar to the flag mixing of EFLAGS and CS used to test

Hi all, I've been looking at finding common ground between the VMI, Xen and other paravirtualization approaches, and after some discussion, we're getting somewhere. These first two patches are the fundamentals, stolen mainly from the VMI patches: removing assumptions about the kernel running in ring 0, and macro-izing all the obvious para-virtualize-needing insns. The third patch is

Hi all, I've been looking at finding common ground between the VMI, Xen and other paravirtualization approaches, and after some discussion, we're getting somewhere. These first two patches are the fundamentals, stolen mainly from the VMI patches: removing assumptions about the kernel running in ring 0, and macro-izing all the obvious para-virtualize-needing insns. The third patch is

Add some convenient segment macros to the kernel. This makes the rather obfuscated 'seg & 4' go away. Patch-keys: i386 segment cleanup Patch-base: 2.6.13-rc5-mm1 Signed-off-by: Zachary Amsden <zach@vmware.com> Index: linux-2.6.13/include/asm-i386/segment.h =================================================================== --- linux-2.6.13.orig/include/asm-i386/segment.h

Add some convenient segment macros to the kernel. This makes the rather obfuscated 'seg & 4' go away. Patch-keys: i386 segment cleanup Patch-base: 2.6.13-rc5-mm1 Signed-off-by: Zachary Amsden <zach@vmware.com> Index: linux-2.6.13/include/asm-i386/segment.h =================================================================== --- linux-2.6.13.orig/include/asm-i386/segment.h

IA-32 linear address translation is loads of fun. While cleaning up the LDT code, I noticed that kprobes code was very bogus with respect to segment handling. Many, many bugs are fixed here. I chose to combine the three separate functions that try to do linear address conversion into one, nice and working functions. All of the versions had bugs. 1) Taking an int3 from v8086 mode could cause

IA-32 linear address translation is loads of fun. While cleaning up the LDT code, I noticed that kprobes code was very bogus with respect to segment handling. Many, many bugs are fixed here. I chose to combine the three separate functions that try to do linear address conversion into one, nice and working functions. All of the versions had bugs. 1) Taking an int3 from v8086 mode could cause

(Andrew, please sit these in the -mm tree for cooking) Create a paravirt.h header for (almost) all the critical operations which need to be replaced with hypervisor calls. For the moment, this simply includes no_paravirt.h, where all the native implementations now live. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Zachary Amsden <zach@vmware.com>

(Andrew, please sit these in the -mm tree for cooking) Create a paravirt.h header for (almost) all the critical operations which need to be replaced with hypervisor calls. For the moment, this simply includes no_paravirt.h, where all the native implementations now live. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Zachary Amsden <zach@vmware.com>

[ Expand, correct and clarify comments; minor code change. ] Most of the time we can simply use the iret instruction to exit the kernel, rather than having to use the iret hypercall - the only exception is if we're returning into vm86 mode, or from delivering an NMI (which we don't support yet). When running native, iret has the behaviour of testing for a pending interrupt atomically

[ Expand, correct and clarify comments; minor code change. ] Most of the time we can simply use the iret instruction to exit the kernel, rather than having to use the iret hypercall - the only exception is if we're returning into vm86 mode, or from delivering an NMI (which we don't support yet). When running native, iret has the behaviour of testing for a pending interrupt atomically

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

xen: use iret directly where possible Most of the time we can simply use the iret instruction to exit the kernel, rather than having to use the iret hypercall - the only exception is if we're returning into vm86 mode, or from delivering an NMI (which we don't support yet). When running native, iret has the behaviour of testing for a pending interrupt atomically with re-enabling

xen: use iret directly where possible Most of the time we can simply use the iret instruction to exit the kernel, rather than having to use the iret hypercall - the only exception is if we're returning into vm86 mode, or from delivering an NMI (which we don't support yet). When running native, iret has the behaviour of testing for a pending interrupt atomically with re-enabling

xen: use iret directly where possible Most of the time we can simply use the iret instruction to exit the kernel, rather than having to use the iret hypercall - the only exception is if we're returning into vm86 mode, or from delivering an NMI (which we don't support yet). When running native, iret has the behaviour of testing for a pending interrupt atomically with re-enabling

i386 Transparent Paravirtualization Patch #2 Changes required to low level fault / system call code for supporting transparent paravirtualization where the kernel may be running at non-zero CPL. The testing of VM_MASK and CS together uses a neat trick which is now extended to support CPL 0,1,2 kernels. Note that assembly code must test against __ESPFIX_SS, the 16-bit stack on interrupts and