linux/arch/powerpc
Bharata B Rao ca9f494267 KVM: PPC: Book3S HV: Support for running secure guests
A pseries guest can be run as secure guest on Ultravisor-enabled
POWER platforms. On such platforms, this driver will be used to manage
the movement of guest pages between the normal memory managed by
hypervisor (HV) and secure memory managed by Ultravisor (UV).

HV is informed about the guest's transition to secure mode via hcalls:

H_SVM_INIT_START: Initiate securing a VM
H_SVM_INIT_DONE: Conclude securing a VM

As part of H_SVM_INIT_START, register all existing memslots with
the UV. H_SVM_INIT_DONE call by UV informs HV that transition of
the guest to secure mode is complete.

These two states (transition to secure mode STARTED and transition
to secure mode COMPLETED) are recorded in kvm->arch.secure_guest.
Setting these states will cause the assembly code that enters the
guest to call the UV_RETURN ucall instead of trying to enter the
guest directly.

Migration of pages betwen normal and secure memory of secure
guest is implemented in H_SVM_PAGE_IN and H_SVM_PAGE_OUT hcalls.

H_SVM_PAGE_IN: Move the content of a normal page to secure page
H_SVM_PAGE_OUT: Move the content of a secure page to normal page

Private ZONE_DEVICE memory equal to the amount of secure memory
available in the platform for running secure guests is created.
Whenever a page belonging to the guest becomes secure, a page from
this private device memory is used to represent and track that secure
page on the HV side. The movement of pages between normal and secure
memory is done via migrate_vma_pages() using UV_PAGE_IN and
UV_PAGE_OUT ucalls.

In order to prevent the device private pages (that correspond to pages
of secure guest) from participating in KSM merging, H_SVM_PAGE_IN
calls ksm_madvise() under read version of mmap_sem. However
ksm_madvise() needs to be under write lock.  Hence we call
kvmppc_svm_page_in with mmap_sem held for writing, and it then
downgrades to a read lock after calling ksm_madvise.

[paulus@ozlabs.org - roll in patch "KVM: PPC: Book3S HV: Take write
 mmap_sem when calling ksm_madvise"]

Signed-off-by: Bharata B Rao <bharata@linux.ibm.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2019-11-28 16:30:02 +11:00
..
boot kbuild: remove ar-option and KBUILD_ARFLAGS 2019-10-01 09:20:33 +09:00
configs powerpc/configs: Enable secure guest support in pseries and ppc64 defconfigs 2019-08-30 09:56:30 +10:00
crypto treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
include KVM: PPC: Book3S HV: Support for running secure guests 2019-11-28 16:30:02 +11:00
kernel powerpc/prom_init: Undo relocation before entering secure mode 2019-10-29 15:12:17 +11:00
kvm KVM: PPC: Book3S HV: Support for running secure guests 2019-11-28 16:30:02 +11:00
lib powerpc/memcpy: Fix stack corruption for smaller sizes 2019-09-12 09:27:00 +10:00
math-emu treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
mm libnvdimm fixes v5.4-rc1 2019-09-29 10:33:41 -07:00
net powerpc/bpf: Fix tail call implementation 2019-11-02 00:32:26 +01:00
oprofile treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 333 2019-06-05 17:37:06 +02:00
perf powerpc/perf: fix imc allocation failure handling 2019-08-20 21:22:20 +10:00
platforms powerpc/powernv: Fix CPU idle to be called with IRQs disabled 2019-10-29 21:47:01 +11:00
purgatory treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 441 2019-06-05 17:37:17 +02:00
sysdev KVM: PPC: Book3S HV: use smp_mb() when setting/clearing host_ipi flag 2019-09-24 12:46:26 +10:00
tools treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
xmon powerpc/xmon: Improve output of XIVE interrupts 2019-09-14 00:58:47 +10:00
Kbuild treewide: Add SPDX license identifier - Kbuild 2019-05-30 11:32:33 -07:00
Kconfig powerpc updates for 5.4 2019-09-20 11:48:06 -07:00
Kconfig.debug powerpc/xmon: add read-only mode 2019-05-03 02:54:57 +10:00
Makefile powerpc updates for 5.4 2019-09-20 11:48:06 -07:00
Makefile.postlink kbuild: add $(BASH) to run scripts with bash-extension 2019-09-04 22:54:13 +09:00