linux/virt/kvm
Sean Christopherson c0db19232c KVM: Assert that mmu_invalidate_in_progress *never* goes negative
Move the assertion on the in-progress invalidation count from the primary
MMU's notifier path to KVM's common notification path, i.e. assert that
the count doesn't go negative even when the invalidation is coming from
KVM itself.

Opportunistically convert the assertion to a KVM_BUG_ON(), i.e. kill only
the affected VM, not the entire kernel.  A corrupted count is fatal to the
VM, e.g. the non-zero (negative) count will cause mmu_invalidate_retry()
to block any and all attempts to install new mappings.  But it's far from
guaranteed that an end() without a start() is fatal or even problematic to
anything other than the target VM, e.g. the underlying bug could simply be
a duplicate call to end().  And it's much more likely that a missed
invalidation, i.e. a potential use-after-free, would manifest as no
notification whatsoever, not an end() without a start().

Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Fuad Tabba <tabba@google.com>
Tested-by: Fuad Tabba <tabba@google.com>
Message-Id: <20231027182217.3615211-3-seanjc@google.com>
Reviewed-by: Kai Huang <kai.huang@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2023-11-13 05:28:37 -05:00
..
async_pf.c mm/gup: remove vmas parameter from get_user_pages_remote() 2023-06-09 16:25:26 -07:00
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: destruct kvm_io_device while unregistering it from kvm_io_bus 2023-06-13 14:18:09 -07:00
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: Support dirty ring in conjunction with bitmap 2022-11-10 13:11:58 +00:00
eventfd.c kvm/eventfd: use list_for_each_entry when deassign ioeventfd 2023-06-13 14:25:39 -07:00
irqchip.c KVM: replace direct irq.h inclusion 2022-11-09 12:31:37 -05:00
Kconfig KVM: Remove CONFIG_HAVE_KVM_ARCH_TLB_FLUSH_ALL 2023-08-17 09:35:14 +01:00
kvm_main.c KVM: Assert that mmu_invalidate_in_progress *never* goes negative 2023-11-13 05:28:37 -05:00
kvm_mm.h kvm: Remove the unused macro KVM_MMU_READ_{,UN}LOCK() 2022-12-27 06:00:51 -05:00
Makefile.kvm KVM: Reinstate gfn_to_pfn_cache with invalidation support 2022-01-07 10:44:44 -05:00
pfncache.c KVM: Skip unnecessary "unmap" if gpc is already valid during refresh 2022-11-30 19:25:24 +00:00
vfio.c kvm/vfio: avoid bouncing the mutex when adding and deleting groups 2023-08-03 12:01:56 -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