Date: Sat, 25 Mar 2017 05:05:12 +0000 (UTC) From: Peter Grehan <grehan@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-stable@freebsd.org, svn-src-stable-11@freebsd.org Subject: svn commit: r315927 - in stable/11/sys: amd64/vmm x86/include x86/x86 Message-ID: <201703250505.v2P55Cx1099042@repo.freebsd.org>
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Author: grehan Date: Sat Mar 25 05:05:12 2017 New Revision: 315927 URL: https://svnweb.freebsd.org/changeset/base/315927 Log: MFC r315361 and r315364: Hide MONITORX/MWAITX from guests. r315361 Add the AMD MONITORX/MWAITX feature definition introduced in Bulldozer/Ryzen CPUs. r315364 Hide the AMD MONITORX/MWAITX capability. Otherwise, recent Linux guests will use these instructions, resulting in #UD exceptions since bhyve doesn't implement MONITOR/MWAIT exits. This fixes boot-time hangs in recent Linux guests on Ryzen CPUs (and probably Bulldozer aka AMD FX as well). Modified: stable/11/sys/amd64/vmm/x86.c stable/11/sys/x86/include/specialreg.h stable/11/sys/x86/x86/identcpu.c Directory Properties: stable/11/ (props changed) Modified: stable/11/sys/amd64/vmm/x86.c ============================================================================== --- stable/11/sys/amd64/vmm/x86.c Sat Mar 25 02:55:13 2017 (r315926) +++ stable/11/sys/amd64/vmm/x86.c Sat Mar 25 05:05:12 2017 (r315927) @@ -176,6 +176,9 @@ x86_emulate_cpuid(struct vm *vm, int vcp /* Don't advertise the OS visible workaround feature */ regs[2] &= ~AMDID2_OSVW; + /* Hide mwaitx/monitorx capability from the guest */ + regs[2] &= ~AMDID2_MWAITX; + /* * Hide rdtscp/ia32_tsc_aux until we know how * to deal with them. Modified: stable/11/sys/x86/include/specialreg.h ============================================================================== --- stable/11/sys/x86/include/specialreg.h Sat Mar 25 02:55:13 2017 (r315926) +++ stable/11/sys/x86/include/specialreg.h Sat Mar 25 05:05:12 2017 (r315927) @@ -227,6 +227,7 @@ #define AMDID2_DBE 0x04000000 #define AMDID2_PTSC 0x08000000 #define AMDID2_PTSCEL2I 0x10000000 +#define AMDID2_MWAITX 0x20000000 /* * CPUID instruction 1 eax info Modified: stable/11/sys/x86/x86/identcpu.c ============================================================================== --- stable/11/sys/x86/x86/identcpu.c Sat Mar 25 02:55:13 2017 (r315926) +++ stable/11/sys/x86/x86/identcpu.c Sat Mar 25 05:05:12 2017 (r315927) @@ -906,7 +906,7 @@ printcpuinfo(void) "\033DBE" /* Data Breakpoint extension */ "\034PTSC" /* Performance TSC */ "\035PL2I" /* L2I perf count */ - "\036<b29>" + "\036MWAITX" /* MONITORX/MWAITX instructions */ "\037<b30>" "\040<b31>" );
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