linux/virt/kvm
Sean Christopherson 9f87791d68 KVM: Drop KVM's API to allow temporarily unmapping gfn=>pfn cache
Drop kvm_gpc_unmap() as it has no users and unclear requirements.  The
API was added as part of the original gfn_to_pfn_cache support, but its
sole usage[*] was never merged.  Fold the guts of kvm_gpc_unmap() into
the deactivate path and drop the API.  Omit acquiring refresh_lock as
as concurrent calls to kvm_gpc_deactivate() are not allowed (this is
not enforced, e.g. via lockdep. due to it being called during vCPU
destruction).

If/when temporary unmapping makes a comeback, the desirable behavior is
likely to restrict temporary unmapping to vCPU-exclusive mappings and
require the vcpu->mutex be held to serialize unmap.  Use of the
refresh_lock to protect unmapping was somewhat specuatively added by
commit 93984f19e7 ("KVM: Fully serialize gfn=>pfn cache refresh via
mutex") to guard against concurrent unmaps, but the primary use case of
the temporary unmap, nested virtualization[*], doesn't actually need or
want concurrent unmaps.

[*] https://lore.kernel.org/all/20211210163625.2886-7-dwmw2@infradead.org

Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
2022-11-30 19:25:24 +00:00
..
async_pf.c KVM: Add helpers to wake/query blocking vCPU 2021-12-08 04:24:54 -05:00
async_pf.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 504 2019-06-19 17:09:56 +02:00
binary_stats.c KVM: stats: remove dead stores 2021-08-13 03:35:15 -04:00
coalesced_mmio.c KVM: mmio: Fix use-after-free Read in kvm_vm_ioctl_unregister_coalesced_mmio 2021-07-14 12:17:56 -04:00
coalesced_mmio.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
dirty_ring.c KVM: Use acquire/release semantics when accessing dirty ring GFN state 2022-09-29 10:23:08 +01:00
eventfd.c KVM: eventfd: Fix false positive RCU usage warning 2022-05-20 09:10:33 -04:00
irqchip.c KVM: replace direct irq.h inclusion 2022-11-09 12:31:37 -05:00
Kconfig KVM: Add KVM_CAP_DIRTY_LOG_RING_ACQ_REL capability and config option 2022-09-29 10:23:08 +01:00
kvm_main.c KVM: x86: avoid memslot check in NX hugepage recovery if it cannot succeed 2022-11-18 11:30:12 -05:00
kvm_mm.h kvm: Add interruptible flag to __gfn_to_pfn_memslot() 2022-11-09 12:31:27 -05:00
Makefile.kvm KVM: Reinstate gfn_to_pfn_cache with invalidation support 2022-01-07 10:44:44 -05:00
pfncache.c KVM: Drop KVM's API to allow temporarily unmapping gfn=>pfn cache 2022-11-30 19:25:24 +00:00
vfio.c vfio: Hold a reference to the iommu_group in kvm for SPAPR 2022-10-07 08:10:52 -06:00
vfio.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00