src/sys/amd64, branch upstream/12.1.0

MFC r350463

2019-09-18T07:25:04Z

In pmap_advise(), when we encounter a superpage mapping, we first demote the mapping and then destroy one of the 4 KB page mappings so that there is a potential trigger for repromotion. Currently, we destroy the first 4 KB page mapping that falls within the (current) superpage mapping or the virtual address range [sva, eva). However, I have found empirically that destroying the last 4 KB mapping produces slightly better results, specifically, more promotions and fewer failed promotion attempts. Accordingly, this revision changes pmap_advise() to destroy the last 4 KB page mapping. It also replaces some nearby uses of boolean_t with bool.

MFC r351727:

2019-09-16T15:21:37Z

Replace PMAP_LARGEMAP_MAX_ADDRESS() with a more general predicate.

MFC r348828

2019-09-15T17:22:29Z

Implement an alternative solution to the amd64 and i386 pmap problem that we previously addressed in r348246 (and MFCed in r348479). This pmap problem also exists on arm64 and riscv. However, the original solution developed for amd64 and i386 cannot be used on arm64 and riscv. In particular, arm64 and riscv do not define a PG_PROMOTED flag in their level 2 PTEs. (A PG_PROMOTED flag makes no sense on arm64, where unlike x86 or riscv we are required to break the old 4KB mappings before making the 2MB mapping; and on riscv there are no unused bits in the PTE to define a PG_PROMOTED flag.) This commit implements an alternative solution that can be used on all four architectures. Moreover, this solution has two other advantages. First, on older AMD processors that required the Erratum 383 workaround, it is less costly. Specifically, it avoids unnecessary calls to pmap_fill_ptp() on a superpage demotion. Second, it enables the elimination of some calls to pagezero() in pmap_kernel_remove_{l2,pde}(). In addition, remove a related stale comment from pmap_enter_{l2,pde}().

MFC r349951, r349994, r349995, r350005, r350023 (by jhibbits), r350478:

2019-09-03T20:04:44Z

Provide protection against starvation of the ll/sc loops when accessing userpace.

MFC r351000: sys/{x86,amd64}: remove one of doubled ;s

2019-09-03T16:26:35Z

MFC r350492: vmx: use C99 bool, not boolean_t

2019-09-03T16:18:07Z

Bhyve's vmm is a self-contained modern component and thus a good candidate for use of C99 types. Sponsored by: The FreeBSD Foundation

MFC r348446:

2019-08-28T08:05:16Z

makesyscalls.sh: always use absolute path for syscalls.conf syscalls.conf is included using "." which per the Open Group: If file does not contain a , the shell shall use the search path specified by PATH to find the directory containing file. POSIX shells don't fall back to the current working directory. Submitted by: Nathaniel Wesley Filardo Reviewed by: bdrewery Sponsored by: DARPA, AFRL Differential Revision: https://reviews.freebsd.org/D20476

Regenerate to add @generated tag in generated files.

2019-08-28T07:43:31Z

This is a manual merge of r347230.

MFC r349594, r349595, r349601: Add driver for NTB in AMD SoC.

2019-08-27T04:13:22Z

This patch is the driver for NTB hardware in AMD SoCs (ported from Linux) and enables the NTB infrastructure like Doorbells, Scratchpads and Memory window in AMD SoC. This driver has been validated using ntb_transport and if_ntb driver already available in FreeBSD. Submitted by: Rajesh Kumar Relnotes: yes

MFC 350551:

2019-08-24T00:35:59Z

Don't reset memory attributes when mapping physical addresses for ACPI. Previously, AcpiOsMemory was using pmap_mapbios which would always map the requested address Write-Back (WB). For several AMD Ryzen laptops, the BIOS uses AcpiOsMemory to directly access the PCI MCFG region in order to access PCI config registers. This has the side effect of remapping the MCFG region in the direct map as WB instead of UC hanging the laptops during boot. On the one laptop I examined in detail, the _PIC global method used to switch from 8259A PICs to I/O APICs uses a pair of PCI config space registers at offset 0x84 in the device at 0:0:0 to as a pair of address/data registers to access an indirect register in the chipset and clear a single bit to switch modes. To fix, alter the semantics of pmap_mapbios() such that it does not modify the attributes of any existing mappings and instead uses the existing attributes. If a new mapping is created, this new mapping uses WB (the default memory attribute). Special thanks to the gentleman whose name I don't have who brought two affected laptops to the hacker lounge at BSDCan. Direct access to the affected systems permitted finding the root cause within an hour or so. PR: 231760, 236899