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author | Linus Torvalds <torvalds@linux-foundation.org> | 2024-03-11 17:44:11 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2024-03-11 17:44:11 -0700 |
commit | 38b334fc767e44816be087b3ec5d84b1438b735f (patch) | |
tree | 6ee0cc2a1f738df713708ab6d83d6d3b44327eda /drivers/iommu | |
parent | 2edfd1046f555db6456514bc8ffe0847537e54f4 (diff) | |
parent | c0935fca6ba4799e5efc6daeee37887e84707d01 (diff) | |
download | linux-stable-38b334fc767e44816be087b3ec5d84b1438b735f.tar.gz linux-stable-38b334fc767e44816be087b3ec5d84b1438b735f.tar.bz2 linux-stable-38b334fc767e44816be087b3ec5d84b1438b735f.zip |
Merge tag 'x86_sev_for_v6.9_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 SEV updates from Borislav Petkov:
- Add the x86 part of the SEV-SNP host support.
This will allow the kernel to be used as a KVM hypervisor capable of
running SNP (Secure Nested Paging) guests. Roughly speaking, SEV-SNP
is the ultimate goal of the AMD confidential computing side,
providing the most comprehensive confidential computing environment
up to date.
This is the x86 part and there is a KVM part which did not get ready
in time for the merge window so latter will be forthcoming in the
next cycle.
- Rework the early code's position-dependent SEV variable references in
order to allow building the kernel with clang and -fPIE/-fPIC and
-mcmodel=kernel
- The usual set of fixes, cleanups and improvements all over the place
* tag 'x86_sev_for_v6.9_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (36 commits)
x86/sev: Disable KMSAN for memory encryption TUs
x86/sev: Dump SEV_STATUS
crypto: ccp - Have it depend on AMD_IOMMU
iommu/amd: Fix failure return from snp_lookup_rmpentry()
x86/sev: Fix position dependent variable references in startup code
crypto: ccp: Make snp_range_list static
x86/Kconfig: Remove CONFIG_AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT
Documentation: virt: Fix up pre-formatted text block for SEV ioctls
crypto: ccp: Add the SNP_SET_CONFIG command
crypto: ccp: Add the SNP_COMMIT command
crypto: ccp: Add the SNP_PLATFORM_STATUS command
x86/cpufeatures: Enable/unmask SEV-SNP CPU feature
KVM: SEV: Make AVIC backing, VMSA and VMCB memory allocation SNP safe
crypto: ccp: Add panic notifier for SEV/SNP firmware shutdown on kdump
iommu/amd: Clean up RMP entries for IOMMU pages during SNP shutdown
crypto: ccp: Handle legacy SEV commands when SNP is enabled
crypto: ccp: Handle non-volatile INIT_EX data when SNP is enabled
crypto: ccp: Handle the legacy TMR allocation when SNP is enabled
x86/sev: Introduce an SNP leaked pages list
crypto: ccp: Provide an API to issue SEV and SNP commands
...
Diffstat (limited to 'drivers/iommu')
-rw-r--r-- | drivers/iommu/amd/amd_iommu.h | 1 | ||||
-rw-r--r-- | drivers/iommu/amd/init.c | 125 |
2 files changed, 101 insertions, 25 deletions
diff --git a/drivers/iommu/amd/amd_iommu.h b/drivers/iommu/amd/amd_iommu.h index 8b3601f285fd..c970eae2313d 100644 --- a/drivers/iommu/amd/amd_iommu.h +++ b/drivers/iommu/amd/amd_iommu.h @@ -164,5 +164,4 @@ void amd_iommu_domain_set_pgtable(struct protection_domain *domain, u64 *root, int mode); struct dev_table_entry *get_dev_table(struct amd_iommu *iommu); -extern bool amd_iommu_snp_en; #endif diff --git a/drivers/iommu/amd/init.c b/drivers/iommu/amd/init.c index c83bd0c2a1c9..480e7681f4f3 100644 --- a/drivers/iommu/amd/init.c +++ b/drivers/iommu/amd/init.c @@ -30,6 +30,7 @@ #include <asm/io_apic.h> #include <asm/irq_remapping.h> #include <asm/set_memory.h> +#include <asm/sev.h> #include <linux/crash_dump.h> @@ -3221,6 +3222,36 @@ out: return true; } +static void iommu_snp_enable(void) +{ +#ifdef CONFIG_KVM_AMD_SEV + if (!cpu_feature_enabled(X86_FEATURE_SEV_SNP)) + return; + /* + * The SNP support requires that IOMMU must be enabled, and is + * not configured in the passthrough mode. + */ + if (no_iommu || iommu_default_passthrough()) { + pr_err("SNP: IOMMU disabled or configured in passthrough mode, SNP cannot be supported.\n"); + return; + } + + amd_iommu_snp_en = check_feature(FEATURE_SNP); + if (!amd_iommu_snp_en) { + pr_err("SNP: IOMMU SNP feature not enabled, SNP cannot be supported.\n"); + return; + } + + pr_info("IOMMU SNP support enabled.\n"); + + /* Enforce IOMMU v1 pagetable when SNP is enabled. */ + if (amd_iommu_pgtable != AMD_IOMMU_V1) { + pr_warn("Forcing use of AMD IOMMU v1 page table due to SNP.\n"); + amd_iommu_pgtable = AMD_IOMMU_V1; + } +#endif +} + /**************************************************************************** * * AMD IOMMU Initialization State Machine @@ -3256,6 +3287,7 @@ static int __init state_next(void) break; case IOMMU_ENABLED: register_syscore_ops(&amd_iommu_syscore_ops); + iommu_snp_enable(); ret = amd_iommu_init_pci(); init_state = ret ? IOMMU_INIT_ERROR : IOMMU_PCI_INIT; break; @@ -3767,40 +3799,85 @@ int amd_iommu_pc_set_reg(struct amd_iommu *iommu, u8 bank, u8 cntr, u8 fxn, u64 return iommu_pc_get_set_reg(iommu, bank, cntr, fxn, value, true); } -#ifdef CONFIG_AMD_MEM_ENCRYPT -int amd_iommu_snp_enable(void) +#ifdef CONFIG_KVM_AMD_SEV +static int iommu_page_make_shared(void *page) { - /* - * The SNP support requires that IOMMU must be enabled, and is - * not configured in the passthrough mode. - */ - if (no_iommu || iommu_default_passthrough()) { - pr_err("SNP: IOMMU is disabled or configured in passthrough mode, SNP cannot be supported"); - return -EINVAL; + unsigned long paddr, pfn; + + paddr = iommu_virt_to_phys(page); + /* Cbit maybe set in the paddr */ + pfn = __sme_clr(paddr) >> PAGE_SHIFT; + + if (!(pfn % PTRS_PER_PMD)) { + int ret, level; + bool assigned; + + ret = snp_lookup_rmpentry(pfn, &assigned, &level); + if (ret) { + pr_warn("IOMMU PFN %lx RMP lookup failed, ret %d\n", pfn, ret); + return ret; + } + + if (!assigned) { + pr_warn("IOMMU PFN %lx not assigned in RMP table\n", pfn); + return -EINVAL; + } + + if (level > PG_LEVEL_4K) { + ret = psmash(pfn); + if (!ret) + goto done; + + pr_warn("PSMASH failed for IOMMU PFN %lx huge RMP entry, ret: %d, level: %d\n", + pfn, ret, level); + return ret; + } } - /* - * Prevent enabling SNP after IOMMU_ENABLED state because this process - * affect how IOMMU driver sets up data structures and configures - * IOMMU hardware. - */ - if (init_state > IOMMU_ENABLED) { - pr_err("SNP: Too late to enable SNP for IOMMU.\n"); - return -EINVAL; +done: + return rmp_make_shared(pfn, PG_LEVEL_4K); +} + +static int iommu_make_shared(void *va, size_t size) +{ + void *page; + int ret; + + if (!va) + return 0; + + for (page = va; page < (va + size); page += PAGE_SIZE) { + ret = iommu_page_make_shared(page); + if (ret) + return ret; } - amd_iommu_snp_en = check_feature(FEATURE_SNP); + return 0; +} + +int amd_iommu_snp_disable(void) +{ + struct amd_iommu *iommu; + int ret; + if (!amd_iommu_snp_en) - return -EINVAL; + return 0; + + for_each_iommu(iommu) { + ret = iommu_make_shared(iommu->evt_buf, EVT_BUFFER_SIZE); + if (ret) + return ret; - pr_info("SNP enabled\n"); + ret = iommu_make_shared(iommu->ppr_log, PPR_LOG_SIZE); + if (ret) + return ret; - /* Enforce IOMMU v1 pagetable when SNP is enabled. */ - if (amd_iommu_pgtable != AMD_IOMMU_V1) { - pr_warn("Force to using AMD IOMMU v1 page table due to SNP\n"); - amd_iommu_pgtable = AMD_IOMMU_V1; + ret = iommu_make_shared((void *)iommu->cmd_sem, PAGE_SIZE); + if (ret) + return ret; } return 0; } +EXPORT_SYMBOL_GPL(amd_iommu_snp_disable); #endif |