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path: root/arch/s390/kernel/uv.c
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2020-04-25s390/protvirt: fix compilation issueClaudio Imbrenda
The kernel fails to compile with CONFIG_PROTECTED_VIRTUALIZATION_GUEST set but CONFIG_KVM unset. This patch fixes the issue by making the needed variable always available. Link: https://lkml.kernel.org/r/20200423120114.2027410-1-imbrenda@linux.ibm.com Fixes: a0f60f843199 ("s390/protvirt: Add sysfs firmware interface for Ultravisor information") Reported-by: kbuild test robot <lkp@intel.com> Reported-by: Philipp Rudo <prudo@linux.ibm.com> Suggested-by: Philipp Rudo <prudo@linux.ibm.com> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Reviewed-by: Vasily Gorbik <gor@linux.ibm.com> Acked-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2020-02-27s390/protvirt: Add sysfs firmware interface for Ultravisor informationJanosch Frank
That information, e.g. the maximum number of guests or installed Ultravisor facilities, is interesting for QEMU, Libvirt and administrators. Let's provide an easily parsable API to get that information. Signed-off-by: Janosch Frank <frankja@linux.ibm.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Reviewed-by: David Hildenbrand <david@redhat.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2020-02-27s390/mm: provide memory management functions for protected KVM guestsClaudio Imbrenda
This provides the basic ultravisor calls and page table handling to cope with secure guests: - provide arch_make_page_accessible - make pages accessible after unmapping of secure guests - provide the ultravisor commands convert to/from secure - provide the ultravisor commands pin/unpin shared - provide callbacks to make pages secure (inacccessible) - we check for the expected pin count to only make pages secure if the host is not accessing them - we fence hugetlbfs for secure pages - add missing radix-tree include into gmap.h The basic idea is that a page can have 3 states: secure, normal or shared. The hypervisor can call into a firmware function called ultravisor that allows to change the state of a page: convert from/to secure. The convert from secure will encrypt the page and make it available to the host and host I/O. The convert to secure will remove the host capability to access this page. The design is that on convert to secure we will wait until writeback and page refs are indicating no host usage. At the same time the convert from secure (export to host) will be called in common code when the refcount or the writeback bit is already set. This avoids races between convert from and to secure. Then there is also the concept of shared pages. Those are kind of secure where the host can still access those pages. We need to be notified when the guest "unshares" such a page, basically doing a convert to secure by then. There is a call "pin shared page" that we use instead of convert from secure when possible. We do use PG_arch_1 as an optimization to minimize the convert from secure/pin shared. Several comments have been added in the code to explain the logic in the relevant places. Co-developed-by: Ulrich Weigand <Ulrich.Weigand@de.ibm.com> Signed-off-by: Ulrich Weigand <Ulrich.Weigand@de.ibm.com> Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Acked-by: David Hildenbrand <david@redhat.com> Acked-by: Cornelia Huck <cohuck@redhat.com> Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> [borntraeger@de.ibm.com: patch merging, splitting, fixing] Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2020-02-27s390/protvirt: add ultravisor initializationVasily Gorbik
Before being able to host protected virtual machines, donate some of the memory to the ultravisor. Besides that the ultravisor might impose addressing limitations for memory used to back protected VM storage. Treat that limit as protected virtualization host's virtual memory limit. Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Reviewed-by: Thomas Huth <thuth@redhat.com> Reviewed-by: David Hildenbrand <david@redhat.com> [borntraeger@de.ibm.com: patch merging, splitting, fixing] Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2020-02-27s390/protvirt: introduce host side setupVasily Gorbik
Add "prot_virt" command line option which controls if the kernel protected VMs support is enabled at early boot time. This has to be done early, because it needs large amounts of memory and will disable some features like STP time sync for the lpar. Extend ultravisor info definitions and expose it via uv_info struct filled in during startup. Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Reviewed-by: Thomas Huth <thuth@redhat.com> Acked-by: David Hildenbrand <david@redhat.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Acked-by: Christian Borntraeger <borntraeger@de.ibm.com> [borntraeger@de.ibm.com: patch merging, splitting, fixing] Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>