src/sys/amd64, branch release/8.2.0

MFC 216679:

2011-01-03T18:22:22Z

Drop the icu_lock spinlock while pausing briefly after masking the interrupt in the I/O APIC before moving it to a different CPU. Approved by: re (kib)

MFC r216255:

2010-12-15T15:25:56Z

Update some comments related to use of amd64 full context switch. In exec_linux_setregs(), use locally cached pointer to pcb to set pcb_full_iret. In set_regs(), note that full return is needed when code that sets segment registers is enabled. Approved by: re (bz)

MFC r216253:

2010-12-15T15:23:25Z

Retire write-only PCB_FULLCTX pcb flag on amd64. Approved by: re (bz)

MFC r216394:

2010-12-15T15:15:42Z

In fpudna()/npxdna(), mark FPU context initialized and optionally mark user FPU context initialized, if current context is user context. It was reversed in r215865, by inadequate change of this code fragment to a call to fpuuserinited()/npxuserinited(). Approved by: re (bz)

MFC: r210780

2010-12-14T20:19:41Z

Rearrange struct pcb to make better use of cache lines. Approved by: re (kib)

Merge r216365 from head to stable/8:

2010-12-13T12:34:35Z

Derive the XENHVM kernel from GENERIC, adding only the options required to support PV drivers (such as xenpci), and non-adptive locking (along with a comment about why). This change eliminates the synchronisation problem between GENERIC and XENHVM, which had become severely rotted in HEAD, and in 8-STABLE included non-production kernel debugging features such as WITNESS. However, it comes at the cost of enabling devices and options that may not be present under Xen (such as random ethernet cards). For now, opt for a simpler kernel configuration file rather than using nooptions/ nodevice to enumerate and eliminate them. This leads to a somewhat larger XENHVM kernel. This is an MFC candidate for 8-STABLE before 8.2, in order to provide a production-worthy XENHVM kernel configuration for amd64. Discussed with: gibbs, cperciva Reported by: Piete Brooks Sponsored by: DARPA, AFRL Approved by: re (kib)

MFC r216231:

2010-12-13T10:40:16Z

Do not leak %rdx value in the previous image to the new image after execve(2). Approved by: re (bz)

MFC: r216159

2010-12-07T18:14:38Z

Do not change CPU ticker frequency if TSC is P-state invariant. Approved by: re (kib)

MFC r209463:

2010-12-03T22:07:07Z

Fix bugs on pc98, use npxgetuserregs() instead of npxgetregs() for get_fpcontext(), and npxsetuserregs() for set_fpcontext). Also, note that usercontext is not initialized anymore in fpstate_drop(). Systematically replace references to npxgetregs() and npxsetregs() by npxgetuserregs() and npxsetuserregs() in comments. MFC r215865: Remove npxgetregs(), npxsetregs(), fpugetregs() and fpusetregs() functions, they are unused. Remove 'user' from npxgetuserregs() etc. names. For {npx,fpu}{get,set}regs(), always use pcb->pcb_user_save for FPU context storage. MFC r216012: Calling fill_fpregs() for curthread is legitimate, and ELF coredump does this. Approved by: re (bz)

MFC: r215753

2010-11-26T21:39:11Z

Reinitialize PAT MSR via pmap_init_pat() while resuming.