src/sys/dev/hyperv/vmbus, branch release/12.3.0

pvclock: Add vDSO support

2021-10-12T16:01:26Z

Add vDSO support for timekeeping devices that support the KVM/XEN paravirtual clock API. Also, expose, in the userspace-accessible '', definitions that will be needed by 'libc' to support 'VDSO_TH_ALGO_X86_PVCLK'. Sponsored by: Juniper Networks, Inc. Sponsored by: Klara, Inc. Reviewed by: kib Differential Revision: https://reviews.freebsd.org/D31418 (cherry picked from commit d4b2d3035a23d5dc468d41151487a8299bf45cdc)

hyperv/vmbus: Update VMBus version 4.0 and 5.0 support.

2021-03-15T05:00:05Z

Add VMBus protocol version 4.0. and 5.0 to support Windows 10 and newer HyperV hosts. For VMBus 4.0 and newer HyperV, the netvsc gpadl teardown must be done after vmbus close. Submitted by: whu MFC after: 2 weeks Sponsored by: Microsoft (cherry picked from commit ace5ce7e701e5a98c23f820d4f126e5c265aa667)

Prevent framebuffer mmio space from being allocated to other devices on HyperV.

2021-03-15T04:47:18Z

On Gen2 VMs, Hyper-V provides mmio space for framebuffer. This mmio address range is not useable for other PCI devices. Currently only efifb driver is using this range without reserving it from system. Therefore, vmbus driver reserves it before any other PCI device drivers start to request mmio addresses. PR: 222996 Submitted by: weh@microsoft.com Reported by: dmitry_kuleshov@ukr.net Reviewed by: decui@microsoft.com Sponsored by: Microsoft (cherry picked from commit c565776195f2f2b62427af07f6b1a9b7670cbc1f)

MFC r357871:

2020-02-20T01:45:55Z

hyperv: Add Hygon Dhyana support.

Eliminate the arena parameter to kmem_free(). Implicitly this corrects an

2018-08-25T19:38:08Z

error in the function hypercall_memfree(), where the wrong arena was being passed to kmem_free(). Introduce a per-page flag, VPO_KMEM_EXEC, to mark physical pages that are mapped in kmem with execute permissions. Use this flag to determine which arena the kmem virtual addresses are returned to. Eliminate UMA_SLAB_KRWX. The introduction of VPO_KMEM_EXEC makes it redundant. Update the nearby comment for UMA_SLAB_KERNEL. Reviewed by: kib, markj Discussed with: jeff Approved by: re (marius) Differential Revision: https://reviews.freebsd.org/D16845

Eliminate kmem_malloc()'s unused arena parameter. (The arena parameter

2018-08-21T16:43:46Z

became unused in FreeBSD 12.x as a side-effect of the NUMA-related changes.) Reviewed by: kib, markj Discussed with: jeff, re@ Differential Revision: https://reviews.freebsd.org/D16825

Use SMAP on amd64.

2018-07-29T20:47:00Z

Ifuncs selectors dispatch copyin(9) family to the suitable variant, to set rflags.AC around userspace access. Rflags.AC bit is cleared in all kernel entry points unconditionally even on machines not supporting SMAP. Reviewed by: jhb Sponsored by: The FreeBSD Foundation Differential revision: https://reviews.freebsd.org/D13838

hyperv: Fix boot-up after malloc() returns memory of NX by default now

2018-07-07T00:41:04Z

FreeBSD VM can't boot up on Hyper-V after the recent malloc change in r335068: Make UMA and malloc(9) return non-executable memory in most cases. The hypercall page here must be executable. Fix the boot-up issue by adding M_EXEC. PR: 229167 Sponsored by: Microsoft

i386 4/4G split.

2018-04-13T20:30:49Z

The change makes the user and kernel address spaces on i386 independent, giving each almost the full 4G of usable virtual addresses except for one PDE at top used for trampoline and per-CPU trampoline stacks, and system structures that must be always mapped, namely IDT, GDT, common TSS and LDT, and process-private TSS and LDT if allocated. By using 1:1 mapping for the kernel text and data, it appeared possible to eliminate assembler part of the locore.S which bootstraps initial page table and KPTmap. The code is rewritten in C and moved into the pmap_cold(). The comment in vmparam.h explains the KVA layout. There is no PCID mechanism available in protected mode, so each kernel/user switch forth and back completely flushes the TLB, except for the trampoline PTD region. The TLB invalidations for userspace becomes trivial, because IPI handlers switch page tables. On the other hand, context switches no longer need to reload %cr3. copyout(9) was rewritten to use vm_fault_quick_hold(). An issue for new copyout(9) is compatibility with wiring user buffers around sysctl handlers. This explains two kind of locks for copyout ptes and accounting of the vslock() calls. The vm_fault_quick_hold() AKA slow path, is only tried after the 'fast path' failed, which temporary changes mapping to the userspace and copies the data to/from small per-cpu buffer in the trampoline. If a page fault occurs during the copy, it is short-circuit by exception.s to not even reach C code. The change was motivated by the need to implement the Meltdown mitigation, but instead of KPTI the full split is done. The i386 architecture already shows the sizing problems, in particular, it is impossible to link clang and lld with debugging. I expect that the issues due to the virtual address space limits would only exaggerate and the split gives more liveness to the platform. Tested by: pho Discussed with: bde Sponsored by: The FreeBSD Foundation MFC after: 1 month Differential revision: https://reviews.freebsd.org/D14633

Correct comment typo in Hyper-V

2018-03-30T02:25:12Z

PR: 226665 Submitted by: Ryo ONODERA MFC after: 3 days