When PCID is disabled, there would throw a panic
when dropPageTables() access to c.PCID without check.
Signed-off-by: Lai Jiangshan <eag0628@gmail.com>
On Arm platform, "setMemoryRegion" has extra permission checks.
In virt/kvm/arm/mmu.c: kvm_arch_prepare_memory_region()
....
if (writable && !(vma->vm_flags & VM_WRITE)) {
ret = -EPERM;
break;
}
....
So, for Arm platform, the "flags" for kvm_memory_region is required.
And on x86 platform, the "flags" can be always set as '0'.
Signed-off-by: Bin Lu <bin.lu@arm.com>
COPYBARA_INTEGRATE_REVIEW=https://github.com/google/gvisor/pull/810 from lubinszARM:pr_setregion 8c99b19cfb0c859c6630a1cfff951db65fcf87ac
PiperOrigin-RevId: 277602603
Based on the guidelines at
https://opensource.google.com/docs/releasing/authors/.
1. $ rg -l "Google LLC" | xargs sed -i 's/Google LLC.*/The gVisor Authors./'
2. Manual fixup of "Google Inc" references.
3. Add AUTHORS file. Authors may request to be added to this file.
4. Point netstack AUTHORS to gVisor AUTHORS. Drop CONTRIBUTORS.
Fixes#209
PiperOrigin-RevId: 245823212
Change-Id: I64530b24ad021a7d683137459cafc510f5ee1de9
This reduces the number of floating point save/restore cycles required (since
we don't need to restore immediately following the switch, this always happens
in a known context) and allows the kernel hooks to capture state. This lets us
remove calls like "Current()".
PiperOrigin-RevId: 219552844
Change-Id: I7676fa2f6c18b9919718458aa888b832a7db8cab
Instead, CPUs will be created dynamically. We also allow a relatively
efficient mechanism for stealing and notifying when a vCPU becomes
available via unlock.
Since the number of vCPUs is no longer fixed at machine creation time,
we make the dirtySet packing more efficient. This has the pleasant side
effect of cutting out the unsafe address space code.
PiperOrigin-RevId: 201266691
Change-Id: I275c73525a4f38e3714b9ac0fd88731c26adfe66
Because of the KVM shadow page table implementation, modifications made
to guest page tables from host mode may not be syncronized correctly,
resulting in undefined behavior. This is a KVM bug: page table pages
should also be tracked for host modifications and resynced appropriately
(e.g. the guest could "DMA" into a page table page in theory).
However, since we can't rely on this being fixed everywhere, workaround
the issue by forcing page table modifications to be in guest mode. This
will generally be the case anyways, but now if an exit occurs during
modifications, we will re-enter and perform the modifications again.
PiperOrigin-RevId: 199587895
Change-Id: I83c20b4cf2a9f9fa56f59f34939601dd34538fb0
Instead of associating a single PCID with each set of page tables (which
will reach the maximum quickly), allow a dynamic pool for each vCPU.
This is the same way that Linux operates. We also split management of
PCIDs out of the page tables themselves for simplicity.
PiperOrigin-RevId: 199585631
Change-Id: I42f3486ada3cb2a26f623c65ac279b473ae63201
This is a refactor of ring0 and ring0/pagetables that changes from
individual arguments to opts structures. This should involve no
functional changes, but sets the stage for subsequent changes.
PiperOrigin-RevId: 198627556
Change-Id: Id4460340f6a73f0c793cd879324398139cd58ae9