linux_dsm_epyc7002/arch/powerpc
Paul Mackerras a2932923cc KVM: PPC: Book3S HV: Provide a method for userspace to read and write the HPT
A new ioctl, KVM_PPC_GET_HTAB_FD, returns a file descriptor.  Reads on
this fd return the contents of the HPT (hashed page table), writes
create and/or remove entries in the HPT.  There is a new capability,
KVM_CAP_PPC_HTAB_FD, to indicate the presence of the ioctl.  The ioctl
takes an argument structure with the index of the first HPT entry to
read out and a set of flags.  The flags indicate whether the user is
intending to read or write the HPT, and whether to return all entries
or only the "bolted" entries (those with the bolted bit, 0x10, set in
the first doubleword).

This is intended for use in implementing qemu's savevm/loadvm and for
live migration.  Therefore, on reads, the first pass returns information
about all HPTEs (or all bolted HPTEs).  When the first pass reaches the
end of the HPT, it returns from the read.  Subsequent reads only return
information about HPTEs that have changed since they were last read.
A read that finds no changed HPTEs in the HPT following where the last
read finished will return 0 bytes.

The format of the data provides a simple run-length compression of the
invalid entries.  Each block of data starts with a header that indicates
the index (position in the HPT, which is just an array), the number of
valid entries starting at that index (may be zero), and the number of
invalid entries following those valid entries.  The valid entries, 16
bytes each, follow the header.  The invalid entries are not explicitly
represented.

Signed-off-by: Paul Mackerras <paulus@samba.org>
[agraf: fix documentation]
Signed-off-by: Alexander Graf <agraf@suse.de>
2012-12-06 01:33:57 +01:00
..
boot Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc 2012-10-06 03:16:12 +09:00
configs UAPI Disintegration 2012-10-09 2012-10-09 15:04:25 +01:00
include KVM: PPC: Book3S HV: Provide a method for userspace to read and write the HPT 2012-12-06 01:33:57 +01:00
kernel Merge commit 'origin/queue' into for-queue 2012-10-31 13:36:18 +01:00
kvm KVM: PPC: Book3S HV: Provide a method for userspace to read and write the HPT 2012-12-06 01:33:57 +01:00
lib powerpc: Fix VMX fix for memcpy case 2012-10-04 18:02:43 +10:00
math-emu powerpc/math_emu/efp: Look for errata handler when type mismatches 2011-10-06 23:36:47 -05:00
mm readahead: fault retry breaks mmap file read random detection 2012-10-09 16:22:47 +09:00
net powerpc: Start using ___PPC_RA/B/S/T where necessary 2012-07-10 19:18:25 +10:00
oprofile mm: use mm->exe_file instead of first VM_EXECUTABLE vma->vm_file 2012-10-09 16:22:18 +09:00
perf Revert "powerpc/perf: Use pmc_overflow() to detect rolled back events" 2012-10-18 10:36:11 +11:00
platforms Merge remote-tracking branch 'master' into queue 2012-10-29 19:15:32 -02:00
sysdev Merge remote-tracking branch 'master' into queue 2012-10-29 19:15:32 -02:00
xmon powerpc: Add an xmon command to dump one or all pacas 2012-09-18 15:02:36 +10:00
Kconfig Merge branch 'modules-next' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux 2012-10-14 13:39:34 -07:00
Kconfig.debug powerpc: IOMMU fault injection 2012-07-10 19:18:59 +10:00
Makefile crypto: nx - move nx build to driver/crypto Makefile 2012-06-27 14:42:00 +08:00
relocs_check.pl powerpc: Process dynamic relocations for kernel 2011-12-20 10:21:08 -05:00