kernel/git/stable/linux-stable.git/arch/arm/kvm, branch linux-4.5.y

arm/arm64: KVM: Enforce Break-Before-Make on Stage-2 page tables

2016-06-01T19:16:57+00:00

commit d4b9e0790aa764c0b01e18d4e8d33e93ba36d51f upstream. The ARM architecture mandates that when changing a page table entry from a valid entry to another valid entry, an invalid entry is first written, TLB invalidated, and only then the new entry being written. The current code doesn't respect this, directly writing the new entry and only then invalidating TLBs. Let's fix it up. Reported-by: Christoffer Dall Signed-off-by: Marc Zyngier Signed-off-by: Christoffer Dall Signed-off-by: Greg Kroah-Hartman

arm/arm64: KVM: Fix ioctl error handling

2016-02-29T09:56:40+00:00

Calling return copy_to_user(...) in an ioctl will not do the right thing if there's a pagefault: copy_to_user returns the number of bytes not copied in this case. Fix up kvm to do return copy_to_user(...)) ? -EFAULT : 0; everywhere. Cc: stable@vger.kernel.org Acked-by: Christoffer Dall Signed-off-by: Michael S. Tsirkin Signed-off-by: Marc Zyngier

arm/arm64: KVM: Feed initialized memory to MMIO accesses

2016-02-24T11:53:09+00:00

On an MMIO access, we always copy the on-stack buffer info the shared "run" structure, even if this is a read access. This ends up leaking up to 8 bytes of uninitialized memory into userspace, depending on the size of the access. An obvious fix for this one is to only perform the copy if this is an actual write. Reviewed-by: Christoffer Dall Signed-off-by: Marc Zyngier

kvm: rename pfn_t to kvm_pfn_t

2016-01-16T01:56:32+00:00

To date, we have implemented two I/O usage models for persistent memory, PMEM (a persistent "ram disk") and DAX (mmap persistent memory into userspace). This series adds a third, DAX-GUP, that allows DAX mappings to be the target of direct-i/o. It allows userspace to coordinate DMA/RDMA from/to persistent memory. The implementation leverages the ZONE_DEVICE mm-zone that went into 4.3-rc1 (also discussed at kernel summit) to flag pages that are owned and dynamically mapped by a device driver. The pmem driver, after mapping a persistent memory range into the system memmap via devm_memremap_pages(), arranges for DAX to distinguish pfn-only versus page-backed pmem-pfns via flags in the new pfn_t type. The DAX code, upon seeing a PFN_DEV+PFN_MAP flagged pfn, flags the resulting pte(s) inserted into the process page tables with a new _PAGE_DEVMAP flag. Later, when get_user_pages() is walking ptes it keys off _PAGE_DEVMAP to pin the device hosting the page range active. Finally, get_page() and put_page() are modified to take references against the device driver established page mapping. Finally, this need for "struct page" for persistent memory requires memory capacity to store the memmap array. Given the memmap array for a large pool of persistent may exhaust available DRAM introduce a mechanism to allocate the memmap from persistent memory. The new "struct vmem_altmap *" parameter to devm_memremap_pages() enables arch_add_memory() to use reserved pmem capacity rather than the page allocator. This patch (of 18): The core has developed a need for a "pfn_t" type [1]. Move the existing pfn_t in KVM to kvm_pfn_t [2]. [1]: https://lists.01.org/pipermail/linux-nvdimm/2015-September/002199.html [2]: https://lists.01.org/pipermail/linux-nvdimm/2015-September/002218.html Signed-off-by: Dan Williams Acked-by: Christoffer Dall Cc: Paolo Bonzini Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

arm/arm64: KVM: Detect vGIC presence at runtime

2015-12-18T12:01:58+00:00

Before commit 662d9715840aef44dcb573b0f9fab9e8319c868a ("arm/arm64: KVM: Kill CONFIG_KVM_ARM_{VGIC,TIMER}") is was possible to compile the kernel without vGIC and vTimer support. Commit message says about possibility to detect vGIC support in runtime, but this has never been implemented. This patch introduces runtime check, restoring the lost functionality. It again allows to use KVM on hardware without vGIC. Interrupt controller has to be emulated in userspace in this case. -ENODEV return code from probe function means there's no GIC at all. -ENXIO happens when, for example, there is GIC node in the device tree, but it does not specify vGIC resources. Any other error code is still treated as full stop because it might mean some really serious problems. Signed-off-by: Pavel Fedin Reviewed-by: Christoffer Dall Signed-off-by: Marc Zyngier

arm64: KVM: Add support for 16-bit VMID

2015-12-18T10:15:12+00:00

The ARMv8.1 architecture extension allows to choose between 8-bit and 16-bit of VMID, so use this capability for KVM. Reviewed-by: Christoffer Dall Signed-off-by: Vladimir Murzin Signed-off-by: Marc Zyngier

arm/arm64: KVM: Remove unreferenced S2_PGD_ORDER

2015-12-18T10:15:11+00:00

Since commit a987370 ("arm64: KVM: Fix stage-2 PGD allocation to have per-page refcounting") there is no reference to S2_PGD_ORDER, so kill it for the good. Acked-by: Christoffer Dall Signed-off-by: Vladimir Murzin Signed-off-by: Marc Zyngier

ARM: KVM: Cleanup exception injection

2015-12-18T10:14:54+00:00

David Binderman reported that the exception injection code had a couple of unused variables lingering around. Upon examination, it looked like this code could do with an anticipated spring cleaning, which amounts to deduplicating the CPSR/SPSR update, and making it look a bit more like the architecture spec. The spurious variables are removed in the process. Reported-by: David Binderman Reviewed-by: Christoffer Dall Signed-off-by: Marc Zyngier

arm64: KVM: Map the kernel RO section into HYP

2015-12-14T11:30:43+00:00

In order to run C code in HYP, we must make sure that the kernel's RO section is mapped into HYP (otherwise things break badly). Signed-off-by: Marc Zyngier Acked-by: Christoffer Dall

KVM: arm/arm64: Count guest exit due to various reasons

2015-12-14T11:30:00+00:00

It would add guest exit statistics to debugfs, this can be helpful while measuring KVM performance. [ Renamed some of the field names - Christoffer ] Signed-off-by: Amit Singh Tomar Signed-off-by: Christoffer Dall