From: "Stanislav" <stlintel@gmail.com>
To: qemu-devel@nongnu.org
Subject: [Qemu-devel] Bochs BIOS writes incorrect value into MTRR MSR
Date: Sat, 10 Oct 2009 14:57:54 +0200 [thread overview]
Message-ID: <000e01ca49a9$4afc7480$e0f55d80$@com> (raw)
In-Reply-To: <Pine.LNX.4.64.0910101555490.3072@linmac.oyster.ru>
Hi All,
Bochs Bios has a bug in setup_mtrr function in rombios.cc
The code:
/* Mark 3.5-4GB as UC, anything not specified defaults to WB */
wrmsr_smp(MTRRphysBase_MSR(0), 0xe0000000ull | 0);
wrmsr_smp(MTRRphysMask_MSR(0), ~(0x20000000ull - 1) | 0x800);
sets reserved bits in the MTRRphysMask MSR which would cause #GP on real
hardware.
The right way is to use physical address size provided in CPUID left
0x80000008 or set up only no more than 32 bit value.
Could somebody help to fix it ?
Thanks,
Stanislav
next prev parent reply other threads:[~2009-10-10 12:57 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-10-10 11:56 [Qemu-devel] Windows host broken malc
2009-10-10 12:57 ` Stanislav [this message]
2009-10-10 14:36 ` TeLeMan
2009-10-10 15:03 ` malc
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