From: "Kirill A. Shutemov" <kirill.shutemov@xxxxxxxxxxxxxxx> Intel TDX doesn't allow VMM to directly access guest private memory. Any memory that is required for communication with VMM must be shared explicitly. The same rule applies for any any DMA to and fromTDX guest. All DMA pages had to marked as shared pages. A generic way to achieve this without any changes to device drivers is to use the SWIOTLB framework. This method of handling is similar to AMD SEV. So extend this support for TDX guest as well. Also since there are some common code between AMD SEV and TDX guest in mem_encrypt_init(), move it to mem_encrypt_common.c and call AMD specific init function from it Signed-off-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx> Reviewed-by: Andi Kleen <ak@xxxxxxxxxxxxxxx> Reviewed-by: Tony Luck <tony.luck@xxxxxxxxx> Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@xxxxxxxxxxxxxxx> --- Changes since v3: * Rebased on top of Tom Lendacky's protected guest changes (https://lore.kernel.org/patchwork/cover/1468760/) Changes since v1: * Removed sme_me_mask check for amd_mem_encrypt_init() in mem_encrypt_init(). arch/x86/include/asm/mem_encrypt_common.h | 2 ++ arch/x86/kernel/tdx.c | 3 +++ arch/x86/mm/mem_encrypt.c | 5 +---- arch/x86/mm/mem_encrypt_common.c | 14 ++++++++++++++ 4 files changed, 20 insertions(+), 4 deletions(-) diff --git a/arch/x86/include/asm/mem_encrypt_common.h b/arch/x86/include/asm/mem_encrypt_common.h index 697bc40a4e3d..48d98a3d64fd 100644 --- a/arch/x86/include/asm/mem_encrypt_common.h +++ b/arch/x86/include/asm/mem_encrypt_common.h @@ -8,11 +8,13 @@ #ifdef CONFIG_AMD_MEM_ENCRYPT bool amd_force_dma_unencrypted(struct device *dev); +void __init amd_mem_encrypt_init(void); #else /* CONFIG_AMD_MEM_ENCRYPT */ static inline bool amd_force_dma_unencrypted(struct device *dev) { return false; } +static inline void amd_mem_encrypt_init(void) {} #endif /* CONFIG_AMD_MEM_ENCRYPT */ #endif diff --git a/arch/x86/kernel/tdx.c b/arch/x86/kernel/tdx.c index b91740a485d6..01b758496e84 100644 --- a/arch/x86/kernel/tdx.c +++ b/arch/x86/kernel/tdx.c @@ -13,6 +13,7 @@ #include <asm/insn.h> #include <asm/insn-eval.h> #include <linux/sched/signal.h> /* force_sig_fault() */ +#include <linux/swiotlb.h> /* TDX Module call Leaf IDs */ #define TDINFO 1 @@ -517,6 +518,8 @@ void __init tdx_early_init(void) legacy_pic = &null_legacy_pic; + swiotlb_force = SWIOTLB_FORCE; + cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "tdg:cpu_hotplug", NULL, tdg_cpu_offline_prepare); diff --git a/arch/x86/mm/mem_encrypt.c b/arch/x86/mm/mem_encrypt.c index 1f7a72ce9d66..cab68d8cc5b0 100644 --- a/arch/x86/mm/mem_encrypt.c +++ b/arch/x86/mm/mem_encrypt.c @@ -491,14 +491,11 @@ static void print_mem_encrypt_feature_info(void) } /* Architecture __weak replacement functions */ -void __init mem_encrypt_init(void) +void __init amd_mem_encrypt_init(void) { if (!sme_me_mask) return; - /* Call into SWIOTLB to update the SWIOTLB DMA buffers */ - swiotlb_update_mem_attributes(); - /* * With SEV, we need to unroll the rep string I/O instructions, * but SEV-ES supports them through the #VC handler. diff --git a/arch/x86/mm/mem_encrypt_common.c b/arch/x86/mm/mem_encrypt_common.c index fdaf09b4a658..2ba19476dc26 100644 --- a/arch/x86/mm/mem_encrypt_common.c +++ b/arch/x86/mm/mem_encrypt_common.c @@ -10,6 +10,7 @@ #include <asm/mem_encrypt_common.h> #include <linux/dma-mapping.h> #include <linux/protected_guest.h> +#include <linux/swiotlb.h> /* Override for DMA direct allocation check - ARCH_HAS_FORCE_DMA_UNENCRYPTED */ bool force_dma_unencrypted(struct device *dev) @@ -22,3 +23,16 @@ bool force_dma_unencrypted(struct device *dev) return false; } + +/* Architecture __weak replacement functions */ +void __init mem_encrypt_init(void) +{ + /* + * For TDX guest or SEV/SME, call into SWIOTLB to update + * the SWIOTLB DMA buffers + */ + if (sme_me_mask || prot_guest_has(PATTR_GUEST_MEM_ENCRYPT)) + swiotlb_update_mem_attributes(); + + amd_mem_encrypt_init(); +} -- 2.25.1
