similar to: [RFC, PATCH 11/24] i386 Vmi segment changes

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

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.

Clean up of patch for letting kernel run other than ring 0: a. Add some comments about the SEGMENT_IS_*_CODE() macros. b. Add a USER_RPL macro. (Code was comparing a value to a mask in some places and to the magic number 3 in other places.) c. Add macros for table indicator field and use them. d. Change the entry.S tests for LDT stack segment to use the macros. Signed-off-by: Chuck Ebbert

Clean up of patch for letting kernel run other than ring 0: a. Add some comments about the SEGMENT_IS_*_CODE() macros. b. Add a USER_RPL macro. (Code was comparing a value to a mask in some places and to the magic number 3 in other places.) c. Add macros for table indicator field and use them. d. Change the entry.S tests for LDT stack segment to use the macros. Signed-off-by: Chuck Ebbert

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

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

[ 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

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

If EBIOS is detected for this drive it tries to read sector size and use it. If error or no EBIOS 512 is assumed. Buffer to read sector size if always allocated into the stack. CHS informations are not readed as not needed and same space not restoring %dl for drive number. Signed-off-by: Frediano Ziglio <frediano.ziglio at citrix.com> --- mbr/gptmbr.S | 42

git://git.zytor.com/users/genec/syslinux.git Branch handoff-mbr-for-hpa This is a piece of code that can be used in place of a MBR or VBR/PBR (master boot record; volume/partition) in order to examine the data handed to the respective boot code. AX, SS, and SP are destroyed before examining anything. I set an internal restriction that limits it to 420 bytes such that it could be used with a

On Sat, Mar 25, 2017 at 09:28:16PM +0100, Thomas Schmitt via Syslinux wrote: > I think it still has good reason to exist. The test > > cmpw $0xaa55, %bx > jne 1f > > could cause a jump which could push a non-zero CX to the stack. Yes. But that can be fixed by putting the "andw $1, %cx" test before the "cmpw $0xaa55, %bx" test. But then if CX is filled

Make paravirt-ops be a pure function pointer struct; we already have assembly code which uses arithmetic by 4 bytes, which means arbitrary structures are not possible here, and they are not needed. Signed-off-by: Zachary Amsden <zach@vmware.com> diff -r a6889086a657 arch/i386/kernel/paravirt.c --- a/arch/i386/kernel/paravirt.c Thu Apr 19 15:44:49 2007 -0700 +++

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

Make paravirt-ops be a pure function pointer struct; we already have assembly code which uses arithmetic by 4 bytes, which means arbitrary structures are not possible here, and they are not needed. Signed-off-by: Zachary Amsden <zach@vmware.com> diff -r a6889086a657 arch/i386/kernel/paravirt.c --- a/arch/i386/kernel/paravirt.c Thu Apr 19 15:44:49 2007 -0700 +++