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* KVM: s390: Enable DAT support for TPROT handlerThomas Huth2014-05-301-0/+2
| | | | | | | | | | | | The TPROT instruction can be used to check the accessability of storage for any kind of logical addresses. So far, our handler only supported real addresses. This patch now also enables support for addresses that have to be translated via DAT first. And while we're at it, change the code to use the common KVM function gfn_to_hva_prot() to check for the validity and writability of the memory page. Signed-off-by: Thomas Huth <thuth@linux.vnet.ibm.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
* KVM: s390: Add a generic function for translating guest addressesThomas Huth2014-05-301-0/+3
| | | | | | | | This patch adds a function for translating logical guest addresses into physical guest addresses without touching the memory at the given location. Signed-off-by: Thomas Huth <thuth@linux.vnet.ibm.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
* KVM: s390: split SIE state guest prefix fieldMichael Mueller2014-05-161-4/+4
| | | | | | | | | | | | | | | This patch splits the SIE state guest prefix at offset 4 into a prefix bit field. Additionally it provides the access functions: - kvm_s390_get_prefix() - kvm_s390_set_prefix() to access the prefix per vcpu. Signed-off-by: Michael Mueller <mimu@linux.vnet.ibm.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com> Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
* KVM: s390: Add a function for checking the low-address protectionThomas Huth2014-04-291-0/+1
| | | | | | | | | | | | The s390 architecture has a special protection mechanism that can be used to prevent write access to the vital data in the low-core memory area. This patch adds a new helper function that can be used to check for such write accesses and in case of protection, it also sets up the exception data accordingly. Signed-off-by: Thomas Huth <thuth@linux.vnet.ibm.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
* KVM: s390: cleanup kvm_s390_real_to_abs()Heiko Carstens2014-04-221-8/+16
| | | | | | | | | Add kerneldoc comment to kvm_s390_real_to_abs() and change the code so it matches the coding style of the rest of gaccess.h. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Reviewed-by: Thomas Huth <thuth@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
* KVM: s390: remove old guest access functionsHeiko Carstens2014-04-221-81/+0
| | | | | | Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Reviewed-by: Thomas Huth <thuth@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
* KVM: s390: make use of ipte lockHeiko Carstens2014-04-221-0/+2
| | | | | | Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Reviewed-by: Thomas Huth <thuth@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
* KVM: s390: add architecture compliant guest access functionsHeiko Carstens2014-04-221-0/+170
| | | | | | | | | | | | | | | | | | | | | | | | | | | The new guest memory access function write_guest() and read_guest() can be used to access guest memory in an architecture compliant way. These functions will look at the vcpu's PSW and select the correct address space for memory access and also perform correct address wrap around. In case DAT is turned on, page tables will be walked otherwise access will happen to real or absolute memory. Any access exception will be recognized and exception data will be stored in the vcpu's kvm_vcpu_arch.pgm member. Subsequently an exception can be injected if necessary. Missing are: - key protection checks - access register mode support - program event recording support This patch also adds write_guest_real(), read_guest_real(), write_guest_absolute() and read_guest_absolute() guest functions which can be used to access real and absolute storage. These functions currently do not perform any access checks, since there is no use case (yet?). Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Reviewed-by: Thomas Huth <thuth@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
* KVM: s390: add lowcore access functionsHeiko Carstens2014-04-221-2/+93
| | | | | | | | | | | | | | | | | put_guest_lc, read_guest_lc and write_guest_lc are guest access functions which shall only be used to access the lowcore of a vcpu. These functions should be used for e.g. interrupt handlers where no guest memory access protection facilities, like key or low address protection, are applicable. At a later point guest vcpu lowcore access should happen via pinned prefix pages, so that these pages can be accessed directly via the kernel mapping. All of these *_lc functions can be removed then. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Reviewed-by: Thomas Huth <thuth@linux.vnet.ibm.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
* KVM: s390: add kvm_s390_logical_to_effective() helperHeiko Carstens2014-04-221-0/+25
| | | | | | | | | | | | | Add kvm_s390_logical_to_effective() helper which converts a guest vcpu's logical storage address to a guest vcpu effective address by applying the rules of the vcpu's addressing mode defined by PSW bits 31 and 32 (extendended and basic addressing mode). Depending on the vcpu's addressing mode the upper 40 bits (24 bit addressing mode), 33 bits (31 bit addressing mode) or no bits (64 bit addressing mode) will be zeroed and the remaining bits will be returned. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
* KVM: s390: Helper for converting real addresses to absoluteThomas Huth2013-09-241-7/+14
| | | | | | | | | Added a separate helper function that translates guest real addresses to guest absolute addresses by applying the prefix of the guest CPU. Signed-off-by: Thomas Huth <thuth@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* s390: Replace weird use of PTR_RET.Rusty Russell2013-07-151-4/+8
| | | | | | | | | | | | | | | | | Saves repeating "(void __force *)__uptr" but it's less clear. Using the output of PTR_RET() to determine the error rather than just testing IS_ERR() is odd. For example, I *assume* __gptr_to_uptr() never returns NULL? Because the __ret would be 0 for the old code. The new version is clearer, IMHO: it would try to get_user() on that address. If you hate this variant, I can just s/PTR_RET/PTR_ERR_OR_ZERO/ instead. Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>
* s390/kvm,gaccess: add address space annotationsHeiko Carstens2013-03-071-10/+11
| | | | | | | | | | | Add missing address space annotations to all put_guest()/get_guest() callers. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Acked-by: Christian Borntraeger <borntraeger@de.ibm.com> Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
* s390/kvm,gaccess: shorten copy_to/from_guest codeHeiko Carstens2013-03-071-253/+41
| | | | | | | | | | | | | | The code can be significantly shortened. There is no functional change, except that for large (> PAGE_SIZE) copies the guest translation would be done more frequently. However, there is not a single user which does this currently. If one gets added later on this functionality can be added easily again. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
* s390/kvm,gaccess: shorten put/get_guest codeHeiko Carstens2013-03-071-114/+39
| | | | | | | | | | | | | | | | | | | | The put_guest_u*/get_guest_u* are nothing but wrappers for the regular put_user/get_user uaccess functions. The only difference is that before accessing user space the guest address must be translated to a user space address. Change the order of arguments for the guest access functions so they match their uaccess parts. Also remove the u* suffix, so we simply have put_guest/get_guest which will automatically use the right size dependent on pointer type of the destination/source that now must be correct. In result the same behaviour as put_user/get_user except that accesses must be aligned. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Acked-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
* s390/kvm,gaccess: fix guest access return code handlingHeiko Carstens2013-03-071-2/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Guest access functions like copy_to/from_guest() call __guestaddr_to_user() which in turn call gmap_fault() in order to translate a guest address to a user space address. In error case __guest_addr_to_user() returns either -EFAULT or -ENOMEM. The copy_to/from_guest functions just pass these return values down to the callers. The -ENOMEM case however is problematic since there are several places which access guest memory like: rc = copy_to_guest(...); if (rc == -EFAULT) error_handling(); So in case of -ENOMEM the code assumes that the guest memory access succeeded even though it failed. This can cause guest data or state corruption. If __guestaddr_to_user() returns -ENOMEM the meaning is that a valid user space mapping exists, but there was not enough memory available when trying to build the guest mapping. In other words an out-of-memory situation occured. For normal user space accesses an out-of-memory situation causes the page fault handler to map -ENOMEM to -EFAULT (see fixup code in do_no_context()). We need to do exactly the same for the kvm gaccess functions. So __guestaddr_to_user() should just map all error codes to -EFAULT. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
* s390/comments: unify copyright messages and remove file namesHeiko Carstens2012-07-201-2/+2
| | | | | | | | | | | | | | 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>
* [S390] Use gmap translation for accessing guest memoryCarsten Otte2011-07-241-68/+175
| | | | | | | | | | This patch removes kvm-s390 internal assumption of a linear mapping of guest address space to user space. Previously, guest memory was translated to user addresses using a fixed offset (gmsor). The new code uses gmap_fault to resolve guest addresses. Signed-off-by: Carsten Otte <cotte@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* KVM: s390: streamline memslot handlingChristian Ehrhardt2009-09-101-11/+12
| | | | | | | | | | | | | This patch relocates the variables kvm-s390 uses to track guest mem addr/size. As discussed dropping the variables at struct kvm_arch level allows to use the common vcpu->request based mechanism to reload guest memory if e.g. changes via set_memory_region. The kick mechanism introduced in this series is used to ensure running vcpus leave guest state to catch the update. Signed-off-by: Christian Ehrhardt <ehrhardt@linux.vnet.ibm.com> Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: s390: Change guestaddr type in gaccessMartin Schwidefsky2008-07-271-29/+33
| | | | | | | | | All registers are unsigned long types. This patch changes all occurences of guestaddr in gaccess from u64 to unsigned long. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
* KVM: s390: arch backend for the kvm kernel moduleHeiko Carstens2008-04-271-0/+274
This patch contains the port of Qumranet's kvm kernel module to IBM zSeries (aka s390x, mainframe) architecture. It uses the mainframe's virtualization instruction SIE to run virtual machines with up to 64 virtual CPUs each. This port is only usable on 64bit host kernels, and can only run 64bit guest kernels. However, running 31bit applications in guest userspace is possible. The following source files are introduced by this patch arch/s390/kvm/kvm-s390.c similar to arch/x86/kvm/x86.c, this implements all arch callbacks for kvm. __vcpu_run calls back into sie64a to enter the guest machine context arch/s390/kvm/sie64a.S assembler function sie64a, which enters guest context via SIE, and switches world before and after that include/asm-s390/kvm_host.h contains all vital data structures needed to run virtual machines on the mainframe include/asm-s390/kvm.h defines kvm_regs and friends for user access to guest register content arch/s390/kvm/gaccess.h functions similar to uaccess to access guest memory arch/s390/kvm/kvm-s390.h header file for kvm-s390 internals, extended by later patches Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Carsten Otte <cotte@de.ibm.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
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