[PATCH 08/12] x86: centralize setting SWIOTLB_FORCE when guest memory encryption is enabled
From: Christoph Hellwig <hch@lst.de>
Date: 2022-03-01 10:59:30
Also in:
linux-arm-kernel, linux-hyperv, linux-iommu, linux-mips, linux-pci, linux-riscv, linux-s390, xen-devel
Subsystem:
hyper-v/azure core and drivers, the rest, x86 architecture (32-bit and 64-bit), x86 mm · Maintainers:
"K. Y. Srinivasan", Haiyang Zhang, Wei Liu, Dexuan Cui, Long Li, Linus Torvalds, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen, Andy Lutomirski, Peter Zijlstra
Move enabling SWIOTLB_FORCE for guest memory encryption into common code. Signed-off-by: Christoph Hellwig <hch@lst.de> --- arch/x86/kernel/cpu/mshyperv.c | 8 -------- arch/x86/kernel/pci-dma.c | 7 +++++++ arch/x86/mm/mem_encrypt_amd.c | 3 --- 3 files changed, 7 insertions(+), 11 deletions(-)
diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c
index 5a99f993e6392..568274917f1cd 100644
--- a/arch/x86/kernel/cpu/mshyperv.c
+++ b/arch/x86/kernel/cpu/mshyperv.c@@ -336,14 +336,6 @@ static void __init ms_hyperv_init_platform(void) swiotlb_unencrypted_base = ms_hyperv.shared_gpa_boundary; #endif } - -#ifdef CONFIG_SWIOTLB - /* - * Enable swiotlb force mode in Isolation VM to - * use swiotlb bounce buffer for dma transaction. - */ - swiotlb_force = SWIOTLB_FORCE; -#endif } if (hv_max_functions_eax >= HYPERV_CPUID_NESTED_FEATURES) {
diff --git a/arch/x86/kernel/pci-dma.c b/arch/x86/kernel/pci-dma.c
index 2ac0ef9c2fb76..7ab7002758396 100644
--- a/arch/x86/kernel/pci-dma.c
+++ b/arch/x86/kernel/pci-dma.c@@ -53,6 +53,13 @@ static void __init pci_swiotlb_detect(void) if (cc_platform_has(CC_ATTR_HOST_MEM_ENCRYPT)) x86_swiotlb_enable = true; + /* + * Guest with guest memory encryption must always do I/O through a + * bounce buffer as the hypervisor can't access arbitrary VM memory. + */ + if (cc_platform_has(CC_ATTR_GUEST_MEM_ENCRYPT)) + swiotlb_force = SWIOTLB_FORCE; + if (swiotlb_force == SWIOTLB_FORCE) x86_swiotlb_enable = true; }
diff --git a/arch/x86/mm/mem_encrypt_amd.c b/arch/x86/mm/mem_encrypt_amd.c
index 2b2d018ea3450..a72942d569cf9 100644
--- a/arch/x86/mm/mem_encrypt_amd.c
+++ b/arch/x86/mm/mem_encrypt_amd.c@@ -191,9 +191,6 @@ void __init sme_early_init(void) /* Update the protection map with memory encryption mask */ for (i = 0; i < ARRAY_SIZE(protection_map); i++) protection_map[i] = pgprot_encrypted(protection_map[i]); - - if (cc_platform_has(CC_ATTR_GUEST_MEM_ENCRYPT)) - swiotlb_force = SWIOTLB_FORCE; } void __init sev_setup_arch(void)
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2.30.2