search for: io_bitmaps

On the vast majority of modern systems, no processes will use the userspsace I/O syscalls, iopl and ioperm. Add a new config option, CONFIG_X86_IOPORT, to support configuring them out of the kernel entirely. Since these syscalls only exist to support rare legacy userspace programs, X86_IOPORT does not depend on EXPERT, though it does still default to y. In addition to saving a significant

This patch series makes it possible to compile out the iopl and ioperm system calls, which allow privileged processes to request permission to directly poke I/O ports from userspace. Nothing on a modern Linux system uses these calls anymore, and anything new should be using /dev/port instead, or better yet writing a driver. Copying the bloat-o-meter stats from the final patch: 32-bit

This patch series makes it possible to compile out the iopl and ioperm system calls, which allow privileged processes to request permission to directly poke I/O ports from userspace. Nothing on a modern Linux system uses these calls anymore, and anything new should be using /dev/port instead, or better yet writing a driver. Copying the bloat-o-meter stats from the final patch: 32-bit

Hi Josh, On Tue, Oct 22, 2013, at 3:35, Josh Triplett wrote: > On the vast majority of modern systems, no processes will use the > userspsace I/O syscalls, iopl and ioperm. Add a new config option, > CONFIG_X86_IOPORT, to support configuring them out of the kernel > entirely. Since these syscalls only exist to support rare legacy > userspace programs, X86_IOPORT does not depend

Hi Josh, On Tue, Oct 22, 2013, at 3:35, Josh Triplett wrote: > On the vast majority of modern systems, no processes will use the > userspsace I/O syscalls, iopl and ioperm. Add a new config option, > CONFIG_X86_IOPORT, to support configuring them out of the kernel > entirely. Since these syscalls only exist to support rare legacy > userspace programs, X86_IOPORT does not depend

The 32-bit and 64-bit versions of copy_thread have functionally identical handling for copying the I/O bitmap, modulo differences in error handling. Clean up the error paths in both by moving the copy of the I/O bitmap to the end, to eliminate the need to free it if subsequent copy steps fail; move the resulting identical code to a static inline in a common header. Signed-off-by: Josh Triplett

The 32-bit and 64-bit versions of copy_thread have functionally identical handling for copying the I/O bitmap, modulo differences in error handling. Clean up the error paths in both by moving the copy of the I/O bitmap to the end, to eliminate the need to free it if subsequent copy steps fail; move the resulting identical code to a static inline in a common header. Signed-off-by: Josh Triplett

On the vast majority of modern systems, no processes will use the userspsace I/O syscalls, iopl and ioperm. Add a new config option, CONFIG_X86_IOPORT, to support configuring them out of the kernel entirely. Most current systems do not run programs using these syscalls, so X86_IOPORT does not depend on EXPERT, though it does still default to y. In addition to saving a significant amount of

I/O from userspace is used to implement usermode virtio driver(s). This has been done independently by Intel, Brocade/Vyatta, and 6Wind. Sorry, it has to stay. On Mon, Oct 21, 2013 at 7:35 PM, Josh Triplett <josh at joshtriplett.org> wrote: > On the vast majority of modern systems, no processes will use the > userspsace I/O syscalls, iopl and ioperm. Add a new config option, >

I/O from userspace is used to implement usermode virtio driver(s). This has been done independently by Intel, Brocade/Vyatta, and 6Wind. Sorry, it has to stay. On Mon, Oct 21, 2013 at 7:35 PM, Josh Triplett <josh at joshtriplett.org> wrote: > On the vast majority of modern systems, no processes will use the > userspsace I/O syscalls, iopl and ioperm. Add a new config option, >

On Wed, Oct 29, 2014 at 9:10 AM, Josh Triplett <josh at joshtriplett.org> wrote: > On the vast majority of modern systems, no processes will use the > userspsace I/O syscalls, iopl and ioperm. Add a new config option, > CONFIG_X86_IOPORT, to support configuring them out of the kernel > entirely. Most current systems do not run programs using these > syscalls, so X86_IOPORT

Commit 111e7b15cf10f6 ("x86/ioperm: Extend IOPL config to control ioperm() as well") reworked the iopl syscall to use I/O bitmaps. Unfortunately this broke Xen PV domains using that syscall as there is currently no I/O bitmap support in PV domains. Add I/O bitmap support via a new paravirt function update_io_bitmap which Xen PV domains can use to update their I/O bitmaps via a

Commit 111e7b15cf10f6 ("x86/ioperm: Extend IOPL config to control ioperm() as well") reworked the iopl syscall to use I/O bitmaps. Unfortunately this broke Xen PV domains using that syscall as there is currently no I/O bitmap support in PV domains. Add I/O bitmap support via a new paravirt function update_io_bitmap which Xen PV domains can use to update their I/O bitmaps via a

On the vast majority of modern systems, no processes will use the userspsace I/O syscalls, iopl and ioperm. Add a new config option, CONFIG_X86_IOPORT, to support configuring them out of the kernel entirely. Most current systems do not run programs using these syscalls, so X86_IOPORT does not depend on EXPERT, though it does still default to y. In addition to saving a significant amount of

On the vast majority of modern systems, no processes will use the userspsace I/O syscalls, iopl and ioperm. Add a new config option, CONFIG_X86_IOPORT, to support configuring them out of the kernel entirely. Most current systems do not run programs using these syscalls, so X86_IOPORT does not depend on EXPERT, though it does still default to y. In addition to saving a significant amount of

The 32-bit and 64-bit versions of copy_thread have functionally identical handling for copying the I/O bitmap, modulo differences in error handling. Clean up the error paths in both by moving the copy of the I/O bitmap to the end, to eliminate the need to free it if subsequent copy steps fail; move the resulting identical code to a static inline in a common header. Signed-off-by: Josh Triplett

The 32-bit and 64-bit versions of copy_thread have functionally identical handling for copying the I/O bitmap, modulo differences in error handling. Clean up the error paths in both by moving the copy of the I/O bitmap to the end, to eliminate the need to free it if subsequent copy steps fail; move the resulting identical code to a static inline in a common header. Signed-off-by: Josh Triplett

This patch series makes it possible to compile out the userspace IO system calls, iopl and ioperm. The first patch does some 32/64 unification in copy_thread to make subsequent changes easier. The second patch simplifies the complex calculation of the TSS segment limit, which also makes it easier to change in the last patch. Patches 3-9 introduce helpers to make it easier to compile out IO.

This patch series makes it possible to compile out the userspace IO system calls, iopl and ioperm. The first patch does some 32/64 unification in copy_thread to make subsequent changes easier. The second patch simplifies the complex calculation of the TSS segment limit, which also makes it easier to change in the last patch. Patches 3-9 introduce helpers to make it easier to compile out IO.

The previous order of relinquish resource is: relinquish_domain_resources() -> vcpu_destroy() -> nvmx_vcpu_destroy(). However some L1 resources like nv_vvmcx and io_bitmaps are free in nvmx_vcpu_destroy(), therefore the relinquish_domain_resources() will not reduce the refcnt of the domain to 0, therefore the latter vcpu release functions will not be called. To fix this issue, we need to release the nv_vvmcx and io_bitmaps in relinquish_domain_resources(). Besides,...