4 files changed, 250 insertions, 0 deletions

diff --git a/Documentation/ia64/kvm.txt b/Documentation/ia64/kvm.txt
new file mode 100644
index 000000000000..bec9d815da33
--- /dev/null
+++ b/Documentation/ia64/kvm.txt
@@ -0,0 +1,82 @@
+Currently, kvm module in EXPERIMENTAL stage on IA64. This means that
+interfaces are not stable enough to use. So, plase had better don't run
+critical applications in virtual machine. We will try our best to make it
+strong in future versions!
+                                Guide: How to boot up guests on kvm/ia64
+
+This guide is to describe how to enable kvm support for IA-64 systems.
+
+1. Get the kvm source from git.kernel.org.
+        Userspace source:
+                git clone git://git.kernel.org/pub/scm/virt/kvm/kvm-userspace.git
+        Kernel Source:
+                git clone git://git.kernel.org/pub/scm/linux/kernel/git/xiantao/kvm-ia64.git
+
+2. Compile the source code.
+        2.1 Compile userspace code:
+                (1)cd ./kvm-userspace
+                (2)./configure
+                (3)cd kernel
+                (4)make sync LINUX= $kernel_dir (kernel_dir is the directory of kernel source.)
+                (5)cd ..
+                (6)make qemu
+                (7)cd qemu; make install
+
+        2.2 Compile kernel source code:
+                (1) cd ./$kernel_dir
+                (2) Make menuconfig
+                (3) Enter into virtualization option, and choose kvm.
+                (4) make
+                (5) Once (4) done, make modules_install
+                (6) Make initrd, and use new kernel to reboot up host machine.
+                (7) Once (6) done, cd $kernel_dir/arch/ia64/kvm
+                (8) insmod kvm.ko; insmod kvm-intel.ko
+
+Note: For step 2, please make sure that host page size == TARGET_PAGE_SIZE of qemu, otherwise, may fail.
+
+3. Get Guest Firmware named as Flash.fd, and put it under right place:
+        (1) If you have the guest firmware (binary) released by Intel Corp for Xen, use it directly.
+
+        (2) If you have no firmware at hand, Please download its source from
+                hg clone http://xenbits.xensource.com/ext/efi-vfirmware.hg
+            you can get the firmware's binary in the directory of efi-vfirmware.hg/binaries.
+
+        (3) Rename the firware you owned to Flash.fd, and copy it to /usr/local/share/qemu
+
+4. Boot up Linux or Windows guests:
+        4.1 Create or install a image for guest boot. If you have xen experience, it should be easy.
+
+        4.2 Boot up guests use the following command.
+                /usr/local/bin/qemu-system-ia64 -smp xx -m 512 -hda $your_image
+                (xx is the number of virtual processors for the guest, now the maximum value is 4)
+
+5. Known possibile issue on some platforms with old Firmware.
+
+If meet strange host crashe issues, try to solve it through either of the following ways:
+
+(1): Upgrade your Firmware to the latest one.
+
+(2): Applying the below patch to kernel source.
+diff --git a/arch/ia64/kernel/pal.S b/arch/ia64/kernel/pal.S
+index 0b53344..f02b0f7 100644
+--- a/arch/ia64/kernel/pal.S
++++ b/arch/ia64/kernel/pal.S
+@@ -84,7 +84,8 @@ GLOBAL_ENTRY(ia64_pal_call_static)
+        mov ar.pfs = loc1
+        mov rp = loc0
+        ;;
+-       srlz.d                          // seralize restoration of psr.l
++       srlz.i                  // seralize restoration of psr.l
++       ;;
+        br.ret.sptk.many b0
+ END(ia64_pal_call_static)
+
+6. Bug report:
+        If you found any issues when use kvm/ia64, Please post the bug info to kvm-ia64-devel mailing list.
+        https://lists.sourceforge.net/lists/listinfo/kvm-ia64-devel/
+
+Thanks for your interest! Let's work together, and make kvm/ia64 stronger and stronger!
+
+
+                                                                Xiantao Zhang <xiantao.zhang@intel.com>
+                                                                                        2008.3.10
diff --git a/Documentation/ioctl-number.txt b/Documentation/ioctl-number.txt
index c18363bd8d11..240ce7a56c40 100644
--- a/Documentation/ioctl-number.txt
+++ b/Documentation/ioctl-number.txt
@@ -183,6 +183,8 @@ Code	Seq#	Include File		Comments
 0xAC    00-1F   linux/raw.h
 0xAD    00      Netfilter device        in development:
                                         <mailto:rusty@rustcorp.com.au>  
+0xAE    all     linux/kvm.h             Kernel-based Virtual Machine
+                                        <mailto:kvm-devel@lists.sourceforge.net>
 0xB0    all     RATIO devices           in development:
                                         <mailto:vgo@ratio.de>
 0xB1    00-1F   PPPoX                   <mailto:mostrows@styx.uwaterloo.ca>
diff --git a/Documentation/powerpc/kvm_440.txt b/Documentation/powerpc/kvm_440.txt
new file mode 100644
index 000000000000..c02a003fa03a
--- /dev/null
+++ b/Documentation/powerpc/kvm_440.txt
@@ -0,0 +1,41 @@
+Hollis Blanchard <hollisb@us.ibm.com>
+15 Apr 2008
+
+Various notes on the implementation of KVM for PowerPC 440:
+
+To enforce isolation, host userspace, guest kernel, and guest userspace all
+run at user privilege level. Only the host kernel runs in supervisor mode.
+Executing privileged instructions in the guest traps into KVM (in the host
+kernel), where we decode and emulate them. Through this technique, unmodified
+440 Linux kernels can be run (slowly) as guests. Future performance work will
+focus on reducing the overhead and frequency of these traps.
+
+The usual code flow is started from userspace invoking an "run" ioctl, which
+causes KVM to switch into guest context. We use IVPR to hijack the host
+interrupt vectors while running the guest, which allows us to direct all
+interrupts to kvmppc_handle_interrupt(). At this point, we could either
+- handle the interrupt completely (e.g. emulate "mtspr SPRG0"), or
+- let the host interrupt handler run (e.g. when the decrementer fires), or
+- return to host userspace (e.g. when the guest performs device MMIO)
+
+Address spaces: We take advantage of the fact that Linux doesn't use the AS=1
+address space (in host or guest), which gives us virtual address space to use
+for guest mappings. While the guest is running, the host kernel remains mapped
+in AS=0, but the guest can only use AS=1 mappings.
+
+TLB entries: The TLB entries covering the host linear mapping remain
+present while running the guest. This reduces the overhead of lightweight
+exits, which are handled by KVM running in the host kernel. We keep three
+copies of the TLB:
+ - guest TLB: contents of the TLB as the guest sees it
+ - shadow TLB: the TLB that is actually in hardware while guest is running
+ - host TLB: to restore TLB state when context switching guest -> host
+When a TLB miss occurs because a mapping was not present in the shadow TLB,
+but was present in the guest TLB, KVM handles the fault without invoking the
+guest. Large guest pages are backed by multiple 4KB shadow pages through this
+mechanism.
+
+IO: MMIO and DCR accesses are emulated by userspace. We use virtio for network
+and block IO, so those drivers must be enabled in the guest. It's possible
+that some qemu device emulation (e.g. e1000 or rtl8139) may also work with
+little effort.
diff --git a/Documentation/s390/kvm.txt b/Documentation/s390/kvm.txt
new file mode 100644
index 000000000000..6f5ceb0f09fc
--- /dev/null
+++ b/Documentation/s390/kvm.txt
@@ -0,0 +1,125 @@
+*** BIG FAT WARNING ***
+The kvm module is currently in EXPERIMENTAL state for s390. This means that
+the interface to the module is not yet considered to remain stable. Thus, be
+prepared that we keep breaking your userspace application and guest
+compatibility over and over again until we feel happy with the result. Make sure
+your guest kernel, your host kernel, and your userspace launcher are in a
+consistent state.
+
+This Documentation describes the unique ioctl calls to /dev/kvm, the resulting
+kvm-vm file descriptors, and the kvm-vcpu file descriptors that differ from x86.
+
+1. ioctl calls to /dev/kvm
+KVM does support the following ioctls on s390 that are common with other
+architectures and do behave the same:
+KVM_GET_API_VERSION
+KVM_CREATE_VM           (*) see note
+KVM_CHECK_EXTENSION
+KVM_GET_VCPU_MMAP_SIZE
+
+Notes:
+* KVM_CREATE_VM may fail on s390, if the calling process has multiple
+threads and has not called KVM_S390_ENABLE_SIE before.
+
+In addition, on s390 the following architecture specific ioctls are supported:
+ioctl:          KVM_S390_ENABLE_SIE
+args:           none
+see also:       include/linux/kvm.h
+This call causes the kernel to switch on PGSTE in the user page table. This
+operation is needed in order to run a virtual machine, and it requires the
+calling process to be single-threaded. Note that the first call to KVM_CREATE_VM
+will implicitly try to switch on PGSTE if the user process has not called
+KVM_S390_ENABLE_SIE before. User processes that want to launch multiple threads
+before creating a virtual machine have to call KVM_S390_ENABLE_SIE, or will
+observe an error calling KVM_CREATE_VM. Switching on PGSTE is a one-time
+operation, is not reversible, and will persist over the entire lifetime of
+the calling process. It does not have any user-visible effect other than a small
+performance penalty.
+
+2. ioctl calls to the kvm-vm file descriptor
+KVM does support the following ioctls on s390 that are common with other
+architectures and do behave the same:
+KVM_CREATE_VCPU
+KVM_SET_USER_MEMORY_REGION      (*) see note
+KVM_GET_DIRTY_LOG               (**) see note
+
+Notes:
+*  kvm does only allow exactly one memory slot on s390, which has to start
+   at guest absolute address zero and at a user address that is aligned on any
+   page boundary. This hardware "limitation" allows us to have a few unique
+   optimizations. The memory slot doesn't have to be filled
+   with memory actually, it may contain sparse holes. That said, with different
+   user memory layout this does still allow a large flexibility when
+   doing the guest memory setup.
+** KVM_GET_DIRTY_LOG doesn't work properly yet. The user will receive an empty
+log. This ioctl call is only needed for guest migration, and we intend to
+implement this one in the future.
+
+In addition, on s390 the following architecture specific ioctls for the kvm-vm
+file descriptor are supported:
+ioctl:          KVM_S390_INTERRUPT
+args:           struct kvm_s390_interrupt *
+see also:       include/linux/kvm.h
+This ioctl is used to submit a floating interrupt for a virtual machine.
+Floating interrupts may be delivered to any virtual cpu in the configuration.
+Only some interrupt types defined in include/linux/kvm.h make sense when
+submitted as floating interrupts. The following interrupts are not considered
+to be useful as floating interrupts, and a call to inject them will result in
+-EINVAL error code: program interrupts and interprocessor signals. Valid
+floating interrupts are:
+KVM_S390_INT_VIRTIO
+KVM_S390_INT_SERVICE
+
+3. ioctl calls to the kvm-vcpu file descriptor
+KVM does support the following ioctls on s390 that are common with other
+architectures and do behave the same:
+KVM_RUN
+KVM_GET_REGS
+KVM_SET_REGS
+KVM_GET_SREGS
+KVM_SET_SREGS
+KVM_GET_FPU
+KVM_SET_FPU
+
+In addition, on s390 the following architecture specific ioctls for the
+kvm-vcpu file descriptor are supported:
+ioctl:          KVM_S390_INTERRUPT
+args:           struct kvm_s390_interrupt *
+see also:       include/linux/kvm.h
+This ioctl is used to submit an interrupt for a specific virtual cpu.
+Only some interrupt types defined in include/linux/kvm.h make sense when
+submitted for a specific cpu. The following interrupts are not considered
+to be useful, and a call to inject them will result in -EINVAL error code:
+service processor calls and virtio interrupts. Valid interrupt types are:
+KVM_S390_PROGRAM_INT
+KVM_S390_SIGP_STOP
+KVM_S390_RESTART
+KVM_S390_SIGP_SET_PREFIX
+KVM_S390_INT_EMERGENCY
+
+ioctl:          KVM_S390_STORE_STATUS
+args:           unsigned long
+see also:       include/linux/kvm.h
+This ioctl stores the state of the cpu at the guest real address given as
+argument, unless one of the following values defined in include/linux/kvm.h
+is given as arguement:
+KVM_S390_STORE_STATUS_NOADDR - the CPU stores its status to the save area in
+absolute lowcore as defined by the principles of operation
+KVM_S390_STORE_STATUS_PREFIXED - the CPU stores its status to the save area in
+its prefix page just like the dump tool that comes with zipl. This is useful
+to create a system dump for use with lkcdutils or crash.
+
+ioctl:          KVM_S390_SET_INITIAL_PSW
+args:           struct kvm_s390_psw *
+see also:       include/linux/kvm.h
+This ioctl can be used to set the processor status word (psw) of a stopped cpu
+prior to running it with KVM_RUN. Note that this call is not required to modify
+the psw during sie intercepts that fall back to userspace because struct kvm_run
+does contain the psw, and this value is evaluated during reentry of KVM_RUN
+after the intercept exit was recognized.
+
+ioctl:          KVM_S390_INITIAL_RESET
+args:           none
+see also:       include/linux/kvm.h
+This ioctl can be used to perform an initial cpu reset as defined by the
+principles of operation. The target cpu has to be in stopped state.