summaryrefslogtreecommitdiff
path: root/arch/s390/include/asm/sclp.h
AgeCommit message (Collapse)AuthorFilesLines
2013-02-14s390/mm: implement software dirty bitsMartin Schwidefsky1-1/+0
The s390 architecture is unique in respect to dirty page detection, it uses the change bit in the per-page storage key to track page modifications. All other architectures track dirty bits by means of page table entries. This property of s390 has caused numerous problems in the past, e.g. see git commit ef5d437f71afdf4a "mm: fix XFS oops due to dirty pages without buffers on s390". To avoid future issues in regard to per-page dirty bits convert s390 to a fault based software dirty bit detection mechanism. All user page table entries which are marked as clean will be hardware read-only, even if the pte is supposed to be writable. A write by the user process will trigger a protection fault which will cause the user pte to be marked as dirty and the hardware read-only bit is removed. With this change the dirty bit in the storage key is irrelevant for Linux as a host, but the storage key is still required for KVM guests. The effect is that page_test_and_clear_dirty and the related code can be removed. The referenced bit in the storage key is still used by the page_test_and_clear_young primitive to provide page age information. For page cache pages of mappings with mapping_cap_account_dirty there will not be any change in behavior as the dirty bit tracking already uses read-only ptes to control the amount of dirty pages. Only for swap cache pages and pages of mappings without mapping_cap_account_dirty there can be additional protection faults. To avoid an excessive number of additional faults the mk_pte primitive checks for PageDirty if the pgprot value allows for writes and pre-dirties the pte. That avoids all additional faults for tmpfs and shmem pages until these pages are added to the swap cache. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2012-11-30s390/pci: PCI hotplug support via SCLPJan Glauber1-0/+2
Add SCLP PCI configure/deconfigure and implement a PCI hotplug controller (s390_pci_hpc). The hotplug controller creates a slot for every PCI function in stand-by or configured state. The PCI functions are named after the PCI function ID (fid). By writing to the power attribute in /sys/bus/pci/slots/<fid>/power the PCI function is moved to stand-by or configured state. If moved to the configured state the device is automatically scanned by the s390 PCI layer. Signed-off-by: Jan Glauber <jang@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2012-07-24Merge tag 'kvm-3.6-1' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds1-0/+2
Pull KVM updates from Avi Kivity: "Highlights include - full big real mode emulation on pre-Westmere Intel hosts (can be disabled with emulate_invalid_guest_state=0) - relatively small ppc and s390 updates - PCID/INVPCID support in guests - EOI avoidance; 3.6 guests should perform better on 3.6 hosts on interrupt intensive workloads) - Lockless write faults during live migration - EPT accessed/dirty bits support for new Intel processors" Fix up conflicts in: - Documentation/virtual/kvm/api.txt: Stupid subchapter numbering, added next to each other. - arch/powerpc/kvm/booke_interrupts.S: PPC asm changes clashing with the KVM fixes - arch/s390/include/asm/sigp.h, arch/s390/kvm/sigp.c: Duplicated commits through the kvm tree and the s390 tree, with subsequent edits in the KVM tree. * tag 'kvm-3.6-1' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (93 commits) KVM: fix race with level interrupts x86, hyper: fix build with !CONFIG_KVM_GUEST Revert "apic: fix kvm build on UP without IOAPIC" KVM guest: switch to apic_set_eoi_write, apic_write apic: add apic_set_eoi_write for PV use KVM: VMX: Implement PCID/INVPCID for guests with EPT KVM: Add x86_hyper_kvm to complete detect_hypervisor_platform check KVM: PPC: Critical interrupt emulation support KVM: PPC: e500mc: Fix tlbilx emulation for 64-bit guests KVM: PPC64: booke: Set interrupt computation mode for 64-bit host KVM: PPC: bookehv: Add ESR flag to Data Storage Interrupt KVM: PPC: bookehv64: Add support for std/ld emulation. booke: Added crit/mc exception handler for e500v2 booke/bookehv: Add host crit-watchdog exception support KVM: MMU: document mmu-lock and fast page fault KVM: MMU: fix kvm_mmu_pagetable_walk tracepoint KVM: MMU: trace fast page fault KVM: MMU: fast path of handling guest page fault KVM: MMU: introduce SPTE_MMU_WRITEABLE bit KVM: MMU: fold tlb flush judgement into mmu_spte_update ...
2012-07-20s390/comments: unify copyright messages and remove file namesHeiko Carstens1-2/+0
Remove the file name from the comment at top of many files. In most cases the file name was wrong anyway, so it's rather pointless. Also unify the IBM copyright statement. We did have a lot of sightly different statements and wanted to change them one after another whenever a file gets touched. However that never happened. Instead people start to take the old/"wrong" statements to use as a template for new files. So unify all of them in one go. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2012-06-14KVM: s390: Perform early event mask processing during bootHeinz Graalfs1-0/+2
For processing under KVM it is required to detect the actual SCLP console type in order to set it as preferred console. Signed-off-by: Heinz Graalfs <graalfs@linux.vnet.ibm.com> Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> Acked-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com> Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-05-18KVM: s390: add capability indicating COW supportChristian Borntraeger1-0/+1
Currently qemu/kvm on s390 uses a guest mapping that does not allow the guest backing page table to be write-protected to support older systems. On those older systems a host write protection fault will be delivered to the guest. Newer systems allow to write-protect the guest backing memory and let the fault be delivered to the host, thus allowing COW. Use a capability bit to tell qemu if that is possible. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2008-08-01[S390] move include/asm-s390 to arch/s390/include/asmMartin Schwidefsky1-0/+58
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>