Re: port-amd64/54962 (cannot boot NetBSD-current on VMware player 15 on Ryzen 5 3600X after sys/arch/x86/x86/cpu_topology.c:r1.18)

[Kengo NAKAHARA <k-nakahara%iij.ad.jp@localhost>]

The following reply was made to PR port-amd64/54962; it has been noted by GNATS.

From: Kengo NAKAHARA <k-nakahara%iij.ad.jp@localhost>
To: gnats-bugs%netbsd.org@localhost, port-amd64-maintainer%netbsd.org@localhost,
        netbsd-bugs%netbsd.org@localhost, gnats-admin%netbsd.org@localhost, maxv%NetBSD.org@localhost,
        knakahara%netbsd.org@localhost
Cc: 
Subject: Re: port-amd64/54962 (cannot boot NetBSD-current on VMware player 15
 on Ryzen 5 3600X after sys/arch/x86/x86/cpu_topology.c:r1.18)
Date: Mon, 17 Feb 2020 19:27:49 +0900

 Hi,
 
 Thank you for your comment.
 
 On 2020/02/16 3:01, maxv%NetBSD.org@localhost wrote:
 > Synopsis: cannot boot NetBSD-current on VMware player 15 on Ryzen 5 3600X after sys/arch/x86/x86/cpu_topology.c:r1.18
 > 
 > State-Changed-From-To: open->feedback
 > State-Changed-By: maxv%NetBSD.org@localhost
 > State-Changed-When: Sat, 15 Feb 2020 18:01:49 +0000
 > State-Changed-Why:
 > I noticed a bug in x86_cpu_topology() some time ago:
 > 
 > 115 		/* Maximum number of LPs sharing a cache (ebx[23:16]). */
 > 116 		x86_cpuid(1, descs);
 > 117 		lp_max = __SHIFTOUT(descs[1], CPUID_HTT_CORES);
 > 
 > The Intel specification (SDM Volume 1) says:
 > 
 > 	"The nearest power-of-2 integer that is not smaller than EBX[23:16] is the
 > 	 number of unique initial APICIDs reserved for addressing different logical
 > 	 processors in a physical package"
 > 
 > So here lp_max should be rounded up to the nearest power-of-2.
 
 I try the fix, however the kernel cannot boot on my environment.
 Hmm, it may have other bug(s)...
 
 
 Thanks,
 
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 Kengo NAKAHARA <k-nakahara%iij.ad.jp@localhost>