This is a note to let you know that I've just added the patch titled iommu/vt-d: Report right snoop capability when using FL for IOVA to the 5.10-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: iommu-vt-d-report-right-snoop-capability-when-using-.patch and it can be found in the queue-5.10 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 6760099b3f2a2aa143d17324a3a0a30f20aff2ec Author: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx> Date: Tue Mar 30 10:11:45 2021 +0800 iommu/vt-d: Report right snoop capability when using FL for IOVA [ Upstream commit 6c00612d0cba10f7d0917cf1f73c945003ed4cd7 ] The Intel VT-d driver checks wrong register to report snoop capablility when using first level page table for GPA to HPA translation. This might lead the IOMMU driver to say that it supports snooping control, but in reality, it does not. Fix this by always setting PASID-table-entry.PGSNP whenever a pasid entry is setting up for GPA to HPA translation so that the IOMMU driver could report snoop capability as long as it runs in the scalable mode. Fixes: b802d070a52a1 ("iommu/vt-d: Use iova over first level") Suggested-by: Rajesh Sankaran <rajesh.sankaran@xxxxxxxxx> Suggested-by: Kevin Tian <kevin.tian@xxxxxxxxx> Suggested-by: Ashok Raj <ashok.raj@xxxxxxxxx> Signed-off-by: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx> Link: https://lore.kernel.org/r/20210330021145.13824-1-baolu.lu@xxxxxxxxxxxxxxx Signed-off-by: Joerg Roedel <jroedel@xxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c index 7e3db4c0324d..3295e5e162a4 100644 --- a/drivers/iommu/intel/iommu.c +++ b/drivers/iommu/intel/iommu.c @@ -656,7 +656,14 @@ static int domain_update_iommu_snooping(struct intel_iommu *skip) rcu_read_lock(); for_each_active_iommu(iommu, drhd) { if (iommu != skip) { - if (!ecap_sc_support(iommu->ecap)) { + /* + * If the hardware is operating in the scalable mode, + * the snooping control is always supported since we + * always set PASID-table-entry.PGSNP bit if the domain + * is managed outside (UNMANAGED). + */ + if (!sm_supported(iommu) && + !ecap_sc_support(iommu->ecap)) { ret = 0; break; } @@ -2599,6 +2606,9 @@ static int domain_setup_first_level(struct intel_iommu *iommu, flags |= (level == 5) ? PASID_FLAG_FL5LP : 0; + if (domain->domain.type == IOMMU_DOMAIN_UNMANAGED) + flags |= PASID_FLAG_PAGE_SNOOP; + return intel_pasid_setup_first_level(iommu, dev, (pgd_t *)pgd, pasid, domain->iommu_did[iommu->seq_id], flags); diff --git a/drivers/iommu/intel/pasid.c b/drivers/iommu/intel/pasid.c index b92af83b79bd..ce4ef2d245e3 100644 --- a/drivers/iommu/intel/pasid.c +++ b/drivers/iommu/intel/pasid.c @@ -411,6 +411,16 @@ static inline void pasid_set_page_snoop(struct pasid_entry *pe, bool value) pasid_set_bits(&pe->val[1], 1 << 23, value << 23); } +/* + * Setup the Page Snoop (PGSNP) field (Bit 88) of a scalable mode + * PASID entry. + */ +static inline void +pasid_set_pgsnp(struct pasid_entry *pe) +{ + pasid_set_bits(&pe->val[1], 1ULL << 24, 1ULL << 24); +} + /* * Setup the First Level Page table Pointer field (Bit 140~191) * of a scalable mode PASID entry. @@ -579,6 +589,9 @@ int intel_pasid_setup_first_level(struct intel_iommu *iommu, } } + if (flags & PASID_FLAG_PAGE_SNOOP) + pasid_set_pgsnp(pte); + pasid_set_domain_id(pte, did); pasid_set_address_width(pte, iommu->agaw); pasid_set_page_snoop(pte, !!ecap_smpwc(iommu->ecap)); @@ -657,6 +670,9 @@ int intel_pasid_setup_second_level(struct intel_iommu *iommu, pasid_set_fault_enable(pte); pasid_set_page_snoop(pte, !!ecap_smpwc(iommu->ecap)); + if (domain->domain.type == IOMMU_DOMAIN_UNMANAGED) + pasid_set_pgsnp(pte); + /* * Since it is a second level only translation setup, we should * set SRE bit as well (addresses are expected to be GPAs). diff --git a/drivers/iommu/intel/pasid.h b/drivers/iommu/intel/pasid.h index 444c0bec221a..086ebd697319 100644 --- a/drivers/iommu/intel/pasid.h +++ b/drivers/iommu/intel/pasid.h @@ -48,6 +48,7 @@ */ #define PASID_FLAG_SUPERVISOR_MODE BIT(0) #define PASID_FLAG_NESTED BIT(1) +#define PASID_FLAG_PAGE_SNOOP BIT(2) /* * The PASID_FLAG_FL5LP flag Indicates using 5-level paging for first-