lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
Open Source and information security mailing list archives
| ||
|
Date: Wed, 29 Mar 2017 08:51:53 -0700 From: Jacob Pan <jacob.jun.pan@...ux.intel.com> To: Joerg Roedel <joro@...tes.org> Cc: iommu@...ts.linux-foundation.org, Joerg Roedel <jroedel@...e.de>, David Woodhouse <dwmw2@...radead.org>, linux-kernel@...r.kernel.org, jacob.jun.pan@...ux.intel.com Subject: Re: [PATCH] iommu/vt-d: Make sure IOMMUs are off when intel_iommu=off On Wed, 29 Mar 2017 17:00:39 +0200 Joerg Roedel <joro@...tes.org> wrote: > From: Joerg Roedel <jroedel@...e.de> > > When booting into a kexec kernel with intel_iommu=off, and > the previous kernel had intel_iommu=on, the IOMMU hardware > is still enabled and gets not disabled by the new kernel. > > This causes the boot to fail because DMA is blocked by the > hardware. Disable the IOMMUs when we find it enabled in the > kexec kernel and boot with intel_iommu=off. > > Signed-off-by: Joerg Roedel <jroedel@...e.de> > --- > drivers/iommu/intel-iommu.c | 18 +++++++++++++++++- > 1 file changed, 17 insertions(+), 1 deletion(-) > > diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c > index d412a31..1662288 100644 > --- a/drivers/iommu/intel-iommu.c > +++ b/drivers/iommu/intel-iommu.c > @@ -4730,6 +4730,15 @@ static int intel_iommu_cpu_dead(unsigned int > cpu) return 0; > } > > +static void intel_disable_iommus(void) > +{ > + struct intel_iommu *iommu = NULL; > + struct dmar_drhd_unit *drhd; > + > + for_each_iommu(iommu, drhd) > + iommu_disable_translation(iommu); should we also disable IR here? i.e. iommu_disable_irq_remapping(iommu); > +} > + > static inline struct intel_iommu *dev_to_intel_iommu(struct device > *dev) { > return container_of(dev, struct intel_iommu, iommu.dev); > @@ -4840,8 +4849,15 @@ int __init intel_iommu_init(void) > goto out_free_dmar; > } > > - if (no_iommu || dmar_disabled) > + if (no_iommu || dmar_disabled) { > + /* > + * Make sure the IOMMUs are switched off, even when > we > + * boot into a kexec kernel and the previous kernel > left > + * them enabled > + */ > + intel_disable_iommus(); > goto out_free_dmar; > + } > > if (list_empty(&dmar_rmrr_units)) > pr_info("No RMRR found\n"); [Jacob Pan]
Powered by blists - more mailing lists