From: Wei Liu <wei.liu@kernel.org>
To: Roman Kisel <romank@linux.microsoft.com>
Cc: namjain@linux.microsoft.com, bp@alien8.de,
dave.hansen@linux.intel.com, decui@microsoft.com,
haiyangz@microsoft.com, kys@microsoft.com,
linux-hyperv@vger.kernel.org, linux-kernel@vger.kernel.org,
mingo@redhat.com, ssengar@linux.microsoft.com,
tglx@linutronix.de, wei.liu@kernel.org, x86@kernel.org
Subject: Re: [PATCH] x86/hyperv/vtl: Stop kernel from probing VTL0 low memory
Date: Wed, 12 Feb 2025 02:17:29 +0000 [thread overview]
Message-ID: <Z6wEuas8LbRVoBP_@liuwe-devbox-debian-v2> (raw)
In-Reply-To: <20250117170141.1351283-1-romank@linux.microsoft.com>
On Fri, Jan 17, 2025 at 09:01:41AM -0800, Roman Kisel wrote:
> > For Linux, running in Hyper-V VTL (Virtual Trust Level), kernel in VTL2
> > tries to access VTL0 low memory in probe_roms. This memory is not
> > described in the e820 map. Initialize probe_roms call to no-ops
> > during boot for VTL2 kernel to avoid this. The issue got identified
> > in OpenVMM which detects invalid accesses initiated from kernel running
> > in VTL2.
> >
> > Co-developed-by: Saurabh Sengar <ssengar@linux.microsoft.com>
> > Signed-off-by: Saurabh Sengar <ssengar@linux.microsoft.com>
> > Signed-off-by: Naman Jain <namjain@linux.microsoft.com>
> > ---
> > arch/x86/hyperv/hv_vtl.c | 1 +
> > 1 file changed, 1 insertion(+)
> >
> > diff --git a/arch/x86/hyperv/hv_vtl.c b/arch/x86/hyperv/hv_vtl.c
> > index 4e1b1e3b5658..3f4e20d7b724 100644
> > --- a/arch/x86/hyperv/hv_vtl.c
> > +++ b/arch/x86/hyperv/hv_vtl.c
> > @@ -30,6 +30,7 @@ void __init hv_vtl_init_platform(void)
> > x86_platform.realmode_init = x86_init_noop;
> > x86_init.irqs.pre_vector_init = x86_init_noop;
> > x86_init.timers.timer_init = x86_init_noop;
> > + x86_init.resources.probe_roms = x86_init_noop;
> >
> > /* Avoid searching for BIOS MP tables */
> > x86_init.mpparse.find_mptable = x86_init_noop;
> >
> > base-commit: 37136bf5c3a6f6b686d74f41837a6406bec6b7bc
> > --
> > 2.43.0
>
> Thanks, Naman!
>
> Tested-by: Roman Kisel <romank@linux.microsoft.com>
> Reviewed-by: Roman Kisel <romank@linux.microsoft.com>
Applied to hyperv-fixes. Thanks.
prev parent reply other threads:[~2025-02-12 2:17 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-01-16 6:12 [PATCH] x86/hyperv/vtl: Stop kernel from probing VTL0 low memory Naman Jain
2025-01-17 17:01 ` Roman Kisel
2025-02-12 2:17 ` Wei Liu [this message]
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