Messages in this thread | | | Subject | Re: [PATCH 3/4] Revert "x86: disable IOMMUs on kernel crash" | From | (Eric W. Biederman) | Date | Sat, 03 Apr 2010 10:49:09 -0700 |
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Joerg Roedel <joro@8bytes.org> writes:
> On Fri, Apr 02, 2010 at 06:27:54PM -0700, Chris Wright wrote: >> This effectively reverts commit 61d047be99757fd9b0af900d7abce9a13a337488. >> >> Disabling the IOMMU can potetially allow DMA transactions to >> complete without being translated. Leave it enabled, and allow >> crash kernel to do the IOMMU reinitialization properly. >> >> Cc: Joerg Roedel <joerg.roedel@amd.com> >> Cc: Eric Biederman <ebiederm@xmission.com> >> Cc: Neil Horman <nhorman@tuxdriver.com> >> Cc: Vivek Goyal <vgoyal@redhat.com> >> Signed-off-by: Chris Wright <chrisw@sous-sol.org> >> --- >> arch/x86/kernel/crash.c | 6 ------ >> 1 file changed, 6 deletions(-) >> >> --- a/arch/x86/kernel/crash.c >> +++ b/arch/x86/kernel/crash.c >> @@ -27,7 +27,6 @@ >> #include <asm/cpu.h> >> #include <asm/reboot.h> >> #include <asm/virtext.h> >> -#include <asm/x86_init.h> >> >> #if defined(CONFIG_SMP) && defined(CONFIG_X86_LOCAL_APIC) >> >> @@ -103,10 +102,5 @@ void native_machine_crash_shutdown(struc >> #ifdef CONFIG_HPET_TIMER >> hpet_disable(); >> #endif >> - >> -#ifdef CONFIG_X86_64 >> - x86_platform.iommu_shutdown(); >> -#endif >> - >> crash_save_cpu(regs, safe_smp_processor_id()); > > Another problem: This also breaks if the kdump kernel has no > iommu-support.
Not a problem. We require a lot of things of the kdump kernel, and it is immediately apparent in a basic sanity test.
Eric
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