| Message ID | 20211009003711.1390019-7-sathyanarayanan.kuppuswamy@linux.intel.com (mailing list archive) |
|---|---|
| State | Not Applicable |
| Delegated to: | Bjorn Helgaas |
| Headers | show |
| Series | Add TDX Guest Support (shared-mm support) | expand |
On 10/8/21 7:37 PM, Kuppuswamy Sathyanarayanan wrote: > From: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> > > Just like MKTME, TDX reassigns bits of the physical address for > metadata. MKTME used several bits for an encryption KeyID. TDX > uses a single bit in guests to communicate whether a physical page > should be protected by TDX as private memory (bit set to 0) or > unprotected and shared with the VMM (bit set to 1). > > __set_memory_enc_dec() is now aware about TDX and sets Shared bit > accordingly following with relevant TDX hypercall. > > Also, Do TDX_ACCEPT_PAGE on every 4k page after mapping the GPA range > when converting memory to private. Using 4k page size limit is due > to current TDX spec restriction. Also, If the GPA (range) was > already mapped as an active, private page, the host VMM may remove > the private page from the TD by following the “Removing TD Private > Pages” sequence in the Intel TDX-module specification [1] to safely > block the mapping(s), flush the TLB and cache, and remove the > mapping(s). > > BUG() if TDX_ACCEPT_PAGE fails (except "previously accepted page" case) > , as the guest is completely hosed if it can't access memory. > > [1] https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fsoftware.intel.com%2Fcontent%2Fdam%2Fdevelop%2Fexternal%2Fus%2Fen%2Fdocuments%2Ftdx-module-1eas-v0.85.039.pdf&data=04%7C01%7Cthomas.lendacky%40amd.com%7C0e667adf5a4042abce3908d98abd07a8%7C3dd8961fe4884e608e11a82d994e183d%7C0%7C0%7C637693367201703893%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&sdata=UGxQ9xBjWsmev7PetX%2BuS0RChkAXyaH7q6JHO9ZiUtY%3D&reserved=0 > > Tested-by: Kai Huang <kai.huang@linux.intel.com> > Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> > Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> > Reviewed-by: Andi Kleen <ak@linux.intel.com> > Reviewed-by: Tony Luck <tony.luck@intel.com> > Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com> ... > diff --git a/arch/x86/mm/mem_encrypt_common.c b/arch/x86/mm/mem_encrypt_common.c > index f063c885b0a5..119a9056efbb 100644 > --- a/arch/x86/mm/mem_encrypt_common.c > +++ b/arch/x86/mm/mem_encrypt_common.c > @@ -9,9 +9,18 @@ > > #include <asm/mem_encrypt_common.h> > #include <linux/dma-mapping.h> > +#include <linux/cc_platform.h> > > /* Override for DMA direct allocation check - ARCH_HAS_FORCE_DMA_UNENCRYPTED */ > bool force_dma_unencrypted(struct device *dev) > { > - return amd_force_dma_unencrypted(dev); > + if (cc_platform_has(CC_ATTR_GUEST_TDX) && > + cc_platform_has(CC_ATTR_GUEST_MEM_ENCRYPT)) > + return true; > + > + if (cc_platform_has(CC_ATTR_GUEST_MEM_ENCRYPT) || > + cc_platform_has(CC_ATTR_HOST_MEM_ENCRYPT)) > + return amd_force_dma_unencrypted(dev); > + > + return false; Assuming the original force_dma_unencrypted() function was moved here or cc_platform.c, then you shouldn't need any changes. Both SEV and TDX require true be returned if CC_ATTR_GUEST_MEM_ENCRYPT returns true. And then TDX should never return true for CC_ATTR_HOST_MEM_ENCRYPT. > } > diff --git a/arch/x86/mm/pat/set_memory.c b/arch/x86/mm/pat/set_memory.c > index 527957586f3c..6c531d5cb5fd 100644 > --- a/arch/x86/mm/pat/set_memory.c > +++ b/arch/x86/mm/pat/set_memory.c > @@ -30,6 +30,7 @@ > #include <asm/proto.h> > #include <asm/memtype.h> > #include <asm/set_memory.h> > +#include <asm/tdx.h> > > #include "../mm_internal.h" > > @@ -1981,8 +1982,10 @@ int set_memory_global(unsigned long addr, int numpages) > __pgprot(_PAGE_GLOBAL), 0); > } > > -static int __set_memory_enc_dec(unsigned long addr, int numpages, bool enc) > +static int __set_memory_protect(unsigned long addr, int numpages, bool protect) > { > + pgprot_t mem_protected_bits, mem_plain_bits; > + enum tdx_map_type map_type; > struct cpa_data cpa; > int ret; > > @@ -1997,8 +2000,25 @@ static int __set_memory_enc_dec(unsigned long addr, int numpages, bool enc) > memset(&cpa, 0, sizeof(cpa)); > cpa.vaddr = &addr; > cpa.numpages = numpages; > - cpa.mask_set = enc ? __pgprot(_PAGE_ENC) : __pgprot(0); > - cpa.mask_clr = enc ? __pgprot(0) : __pgprot(_PAGE_ENC); > + > + if (cc_platform_has(CC_ATTR_GUEST_SHARED_MAPPING_INIT)) { > + mem_protected_bits = __pgprot(0); > + mem_plain_bits = pgprot_cc_shared_mask(); How about having generic versions for both shared and private that return the proper value for SEV or TDX. Then this remains looking similar to as it does now, just replacing the __pgprot() calls with the appropriate pgprot_cc_{shared,private}_mask(). Thanks, Tom > + } else { > + mem_protected_bits = __pgprot(_PAGE_ENC); > + mem_plain_bits = __pgprot(0); > + } > + > + if (protect) { > + cpa.mask_set = mem_protected_bits; > + cpa.mask_clr = mem_plain_bits; > + map_type = TDX_MAP_PRIVATE; > + } else { > + cpa.mask_set = mem_plain_bits; > + cpa.mask_clr = mem_protected_bits; > + map_type = TDX_MAP_SHARED; > + } > + > cpa.pgd = init_mm.pgd; > > /* Must avoid aliasing mappings in the highmem code */ > @@ -2006,9 +2026,17 @@ static int __set_memory_enc_dec(unsigned long addr, int numpages, bool enc) > vm_unmap_aliases(); > > /* > - * Before changing the encryption attribute, we need to flush caches. > + * Before changing the encryption attribute, flush caches. > + * > + * For TDX, guest is responsible for flushing caches on private->shared > + * transition. VMM is responsible for flushing on shared->private. > */ > - cpa_flush(&cpa, !this_cpu_has(X86_FEATURE_SME_COHERENT)); > + if (cc_platform_has(CC_ATTR_GUEST_TDX)) { > + if (map_type == TDX_MAP_SHARED) > + cpa_flush(&cpa, 1); > + } else { > + cpa_flush(&cpa, !this_cpu_has(X86_FEATURE_SME_COHERENT)); > + } > > ret = __change_page_attr_set_clr(&cpa, 1); > > @@ -2021,18 +2049,21 @@ static int __set_memory_enc_dec(unsigned long addr, int numpages, bool enc) > */ > cpa_flush(&cpa, 0); > > + if (!ret && cc_platform_has(CC_ATTR_GUEST_SHARED_MAPPING_INIT)) > + ret = tdx_hcall_gpa_intent(__pa(addr), numpages, map_type); > + > return ret; > } > > int set_memory_encrypted(unsigned long addr, int numpages) > { > - return __set_memory_enc_dec(addr, numpages, true); > + return __set_memory_protect(addr, numpages, true); > } > EXPORT_SYMBOL_GPL(set_memory_encrypted); > > int set_memory_decrypted(unsigned long addr, int numpages) > { > - return __set_memory_enc_dec(addr, numpages, false); > + return __set_memory_protect(addr, numpages, false); > } > EXPORT_SYMBOL_GPL(set_memory_decrypted); > >
On 10/20/21 9:33 AM, Tom Lendacky wrote: > On 10/8/21 7:37 PM, Kuppuswamy Sathyanarayanan wrote: >> From: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> >> >> Just like MKTME, TDX reassigns bits of the physical address for >> metadata. MKTME used several bits for an encryption KeyID. TDX >> uses a single bit in guests to communicate whether a physical page >> should be protected by TDX as private memory (bit set to 0) or >> unprotected and shared with the VMM (bit set to 1). >> >> __set_memory_enc_dec() is now aware about TDX and sets Shared bit >> accordingly following with relevant TDX hypercall. >> >> Also, Do TDX_ACCEPT_PAGE on every 4k page after mapping the GPA range >> when converting memory to private. Using 4k page size limit is due >> to current TDX spec restriction. Also, If the GPA (range) was >> already mapped as an active, private page, the host VMM may remove >> the private page from the TD by following the “Removing TD Private >> Pages” sequence in the Intel TDX-module specification [1] to safely >> block the mapping(s), flush the TLB and cache, and remove the >> mapping(s). >> >> BUG() if TDX_ACCEPT_PAGE fails (except "previously accepted page" case) >> , as the guest is completely hosed if it can't access memory. >> >> [1] >> https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fsoftware.intel.com%2Fcontent%2Fdam%2Fdevelop%2Fexternal%2Fus%2Fen%2Fdocuments%2Ftdx-module-1eas-v0.85.039.pdf&data=04%7C01%7Cthomas.lendacky%40amd.com%7C0e667adf5a4042abce3908d98abd07a8%7C3dd8961fe4884e608e11a82d994e183d%7C0%7C0%7C637693367201703893%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&sdata=UGxQ9xBjWsmev7PetX%2BuS0RChkAXyaH7q6JHO9ZiUtY%3D&reserved=0 >> >> >> Tested-by: Kai Huang <kai.huang@linux.intel.com> >> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> >> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> >> Reviewed-by: Andi Kleen <ak@linux.intel.com> >> Reviewed-by: Tony Luck <tony.luck@intel.com> >> Signed-off-by: Kuppuswamy Sathyanarayanan >> <sathyanarayanan.kuppuswamy@linux.intel.com> > > ... > >> diff --git a/arch/x86/mm/mem_encrypt_common.c >> b/arch/x86/mm/mem_encrypt_common.c >> index f063c885b0a5..119a9056efbb 100644 >> --- a/arch/x86/mm/mem_encrypt_common.c >> +++ b/arch/x86/mm/mem_encrypt_common.c >> @@ -9,9 +9,18 @@ >> #include <asm/mem_encrypt_common.h> >> #include <linux/dma-mapping.h> >> +#include <linux/cc_platform.h> >> /* Override for DMA direct allocation check - >> ARCH_HAS_FORCE_DMA_UNENCRYPTED */ >> bool force_dma_unencrypted(struct device *dev) >> { >> - return amd_force_dma_unencrypted(dev); >> + if (cc_platform_has(CC_ATTR_GUEST_TDX) && >> + cc_platform_has(CC_ATTR_GUEST_MEM_ENCRYPT)) >> + return true; >> + >> + if (cc_platform_has(CC_ATTR_GUEST_MEM_ENCRYPT) || >> + cc_platform_has(CC_ATTR_HOST_MEM_ENCRYPT)) >> + return amd_force_dma_unencrypted(dev); >> + >> + return false; > > Assuming the original force_dma_unencrypted() function was moved here or > cc_platform.c, then you shouldn't need any changes. Both SEV and TDX > require true be returned if CC_ATTR_GUEST_MEM_ENCRYPT returns true. And > then TDX should never return true for CC_ATTR_HOST_MEM_ENCRYPT. For non TDX case, in CC_ATTR_HOST_MEM_ENCRYPT, we should still call amd_force_dma_unencrypted() right? > >> } >> diff --git a/arch/x86/mm/pat/set_memory.c b/arch/x86/mm/pat/set_memory.c >> index 527957586f3c..6c531d5cb5fd 100644 >> --- a/arch/x86/mm/pat/set_memory.c >> +++ b/arch/x86/mm/pat/set_memory.c >> @@ -30,6 +30,7 @@ >> #include <asm/proto.h> >> #include <asm/memtype.h> >> #include <asm/set_memory.h> >> +#include <asm/tdx.h> >> #include "../mm_internal.h" >> @@ -1981,8 +1982,10 @@ int set_memory_global(unsigned long addr, int >> numpages) >> __pgprot(_PAGE_GLOBAL), 0); >> } >> -static int __set_memory_enc_dec(unsigned long addr, int numpages, >> bool enc) >> +static int __set_memory_protect(unsigned long addr, int numpages, >> bool protect) >> { >> + pgprot_t mem_protected_bits, mem_plain_bits; >> + enum tdx_map_type map_type; >> struct cpa_data cpa; >> int ret; >> @@ -1997,8 +2000,25 @@ static int __set_memory_enc_dec(unsigned long >> addr, int numpages, bool enc) >> memset(&cpa, 0, sizeof(cpa)); >> cpa.vaddr = &addr; >> cpa.numpages = numpages; >> - cpa.mask_set = enc ? __pgprot(_PAGE_ENC) : __pgprot(0); >> - cpa.mask_clr = enc ? __pgprot(0) : __pgprot(_PAGE_ENC); >> + >> + if (cc_platform_has(CC_ATTR_GUEST_SHARED_MAPPING_INIT)) { >> + mem_protected_bits = __pgprot(0); >> + mem_plain_bits = pgprot_cc_shared_mask(); > > How about having generic versions for both shared and private that > return the proper value for SEV or TDX. Then this remains looking > similar to as it does now, just replacing the __pgprot() calls with the > appropriate pgprot_cc_{shared,private}_mask(). Makes sense. > > Thanks, > Tom > >> + } else { >> + mem_protected_bits = __pgprot(_PAGE_ENC); >> + mem_plain_bits = __pgprot(0); >> + } >> + >> + if (protect) { >> + cpa.mask_set = mem_protected_bits; >> + cpa.mask_clr = mem_plain_bits; >> + map_type = TDX_MAP_PRIVATE; >> + } else { >> + cpa.mask_set = mem_plain_bits; >> + cpa.mask_clr = mem_protected_bits; >> + map_type = TDX_MAP_SHARED; >> + } >> + >> cpa.pgd = init_mm.pgd; >> /* Must avoid aliasing mappings in the highmem code */ >> @@ -2006,9 +2026,17 @@ static int __set_memory_enc_dec(unsigned long >> addr, int numpages, bool enc) >> vm_unmap_aliases(); >> /* >> - * Before changing the encryption attribute, we need to flush >> caches. >> + * Before changing the encryption attribute, flush caches. >> + * >> + * For TDX, guest is responsible for flushing caches on >> private->shared >> + * transition. VMM is responsible for flushing on shared->private. >> */ >> - cpa_flush(&cpa, !this_cpu_has(X86_FEATURE_SME_COHERENT)); >> + if (cc_platform_has(CC_ATTR_GUEST_TDX)) { >> + if (map_type == TDX_MAP_SHARED) >> + cpa_flush(&cpa, 1); >> + } else { >> + cpa_flush(&cpa, !this_cpu_has(X86_FEATURE_SME_COHERENT)); >> + } >> ret = __change_page_attr_set_clr(&cpa, 1); >> @@ -2021,18 +2049,21 @@ static int __set_memory_enc_dec(unsigned long >> addr, int numpages, bool enc) >> */ >> cpa_flush(&cpa, 0); >> + if (!ret && cc_platform_has(CC_ATTR_GUEST_SHARED_MAPPING_INIT)) >> + ret = tdx_hcall_gpa_intent(__pa(addr), numpages, map_type); >> + >> return ret; >> } >> int set_memory_encrypted(unsigned long addr, int numpages) >> { >> - return __set_memory_enc_dec(addr, numpages, true); >> + return __set_memory_protect(addr, numpages, true); >> } >> EXPORT_SYMBOL_GPL(set_memory_encrypted); >> int set_memory_decrypted(unsigned long addr, int numpages) >> { >> - return __set_memory_enc_dec(addr, numpages, false); >> + return __set_memory_protect(addr, numpages, false); >> } >> EXPORT_SYMBOL_GPL(set_memory_decrypted); >>
On 10/20/21 11:45 AM, Sathyanarayanan Kuppuswamy wrote: > On 10/20/21 9:33 AM, Tom Lendacky wrote: >> On 10/8/21 7:37 PM, Kuppuswamy Sathyanarayanan wrote: ... >>> bool force_dma_unencrypted(struct device *dev) >>> { >>> - return amd_force_dma_unencrypted(dev); >>> + if (cc_platform_has(CC_ATTR_GUEST_TDX) && >>> + cc_platform_has(CC_ATTR_GUEST_MEM_ENCRYPT)) >>> + return true; >>> + >>> + if (cc_platform_has(CC_ATTR_GUEST_MEM_ENCRYPT) || >>> + cc_platform_has(CC_ATTR_HOST_MEM_ENCRYPT)) >>> + return amd_force_dma_unencrypted(dev); >>> + >>> + return false; >> >> Assuming the original force_dma_unencrypted() function was moved here or >> cc_platform.c, then you shouldn't need any changes. Both SEV and TDX >> require true be returned if CC_ATTR_GUEST_MEM_ENCRYPT returns true. And >> then TDX should never return true for CC_ATTR_HOST_MEM_ENCRYPT. > > > For non TDX case, in CC_ATTR_HOST_MEM_ENCRYPT, we should still call > amd_force_dma_unencrypted() right? What I'm saying is that you wouldn't have amd_force_dma_unencrypted(). I think the whole force_dma_unencrypted() can exist as-is in a different file, whether that's cc_platform.c or mem_encrypt_common.c. It will return true for an SEV or TDX guest, true for an SME host based on the DMA mask or else false. That should work just fine for TDX. Thanks, Tom > >> >>> } >>> diff --git a/arch/x86/mm/pat/set_memory.c b/arch/x86/mm/pat/set_memory.c >>> index 527957586f3c..6c531d5cb5fd 100644 >>> --- a/arch/x86/mm/pat/set_memory.c >>> +++ b/arch/x86/mm/pat/set_memory.c >>> @@ -30,6 +30,7 @@ >>> #include <asm/proto.h> >>> #include <asm/memtype.h> >>> #include <asm/set_memory.h> >>> +#include <asm/tdx.h> >>> #include "../mm_internal.h" >>> @@ -1981,8 +1982,10 @@ int set_memory_global(unsigned long addr, int >>> numpages) >>> __pgprot(_PAGE_GLOBAL), 0); >>> } >>> -static int __set_memory_enc_dec(unsigned long addr, int numpages, bool >>> enc) >>> +static int __set_memory_protect(unsigned long addr, int numpages, bool >>> protect) >>> { >>> + pgprot_t mem_protected_bits, mem_plain_bits; >>> + enum tdx_map_type map_type; >>> struct cpa_data cpa; >>> int ret; >>> @@ -1997,8 +2000,25 @@ static int __set_memory_enc_dec(unsigned long >>> addr, int numpages, bool enc) >>> memset(&cpa, 0, sizeof(cpa)); >>> cpa.vaddr = &addr; >>> cpa.numpages = numpages; >>> - cpa.mask_set = enc ? __pgprot(_PAGE_ENC) : __pgprot(0); >>> - cpa.mask_clr = enc ? __pgprot(0) : __pgprot(_PAGE_ENC); >>> + >>> + if (cc_platform_has(CC_ATTR_GUEST_SHARED_MAPPING_INIT)) { >>> + mem_protected_bits = __pgprot(0); >>> + mem_plain_bits = pgprot_cc_shared_mask(); >> >> How about having generic versions for both shared and private that >> return the proper value for SEV or TDX. Then this remains looking >> similar to as it does now, just replacing the __pgprot() calls with the >> appropriate pgprot_cc_{shared,private}_mask(). > > Makes sense. > >> >> Thanks, >> Tom >> >>> + } else { >>> + mem_protected_bits = __pgprot(_PAGE_ENC); >>> + mem_plain_bits = __pgprot(0); >>> + } >>> + >>> + if (protect) { >>> + cpa.mask_set = mem_protected_bits; >>> + cpa.mask_clr = mem_plain_bits; >>> + map_type = TDX_MAP_PRIVATE; >>> + } else { >>> + cpa.mask_set = mem_plain_bits; >>> + cpa.mask_clr = mem_protected_bits; >>> + map_type = TDX_MAP_SHARED; >>> + } >>> + >>> cpa.pgd = init_mm.pgd; >>> /* Must avoid aliasing mappings in the highmem code */ >>> @@ -2006,9 +2026,17 @@ static int __set_memory_enc_dec(unsigned long >>> addr, int numpages, bool enc) >>> vm_unmap_aliases(); >>> /* >>> - * Before changing the encryption attribute, we need to flush caches. >>> + * Before changing the encryption attribute, flush caches. >>> + * >>> + * For TDX, guest is responsible for flushing caches on >>> private->shared >>> + * transition. VMM is responsible for flushing on shared->private. >>> */ >>> - cpa_flush(&cpa, !this_cpu_has(X86_FEATURE_SME_COHERENT)); >>> + if (cc_platform_has(CC_ATTR_GUEST_TDX)) { >>> + if (map_type == TDX_MAP_SHARED) >>> + cpa_flush(&cpa, 1); >>> + } else { >>> + cpa_flush(&cpa, !this_cpu_has(X86_FEATURE_SME_COHERENT)); >>> + } >>> ret = __change_page_attr_set_clr(&cpa, 1); >>> @@ -2021,18 +2049,21 @@ static int __set_memory_enc_dec(unsigned long >>> addr, int numpages, bool enc) >>> */ >>> cpa_flush(&cpa, 0); >>> + if (!ret && cc_platform_has(CC_ATTR_GUEST_SHARED_MAPPING_INIT)) >>> + ret = tdx_hcall_gpa_intent(__pa(addr), numpages, map_type); >>> + >>> return ret; >>> } >>> int set_memory_encrypted(unsigned long addr, int numpages) >>> { >>> - return __set_memory_enc_dec(addr, numpages, true); >>> + return __set_memory_protect(addr, numpages, true); >>> } >>> EXPORT_SYMBOL_GPL(set_memory_encrypted); >>> int set_memory_decrypted(unsigned long addr, int numpages) >>> { >>> - return __set_memory_enc_dec(addr, numpages, false); >>> + return __set_memory_protect(addr, numpages, false); >>> } >>> EXPORT_SYMBOL_GPL(set_memory_decrypted); >>> >
On 10/20/21 10:22 AM, Tom Lendacky wrote: >> >> For non TDX case, in CC_ATTR_HOST_MEM_ENCRYPT, we should still call >> amd_force_dma_unencrypted() right? > > What I'm saying is that you wouldn't have amd_force_dma_unencrypted(). I > think the whole force_dma_unencrypted() can exist as-is in a different > file, whether that's cc_platform.c or mem_encrypt_common.c. > > It will return true for an SEV or TDX guest, true for an SME host based > on the DMA mask or else false. That should work just fine for TDX. Got it. Thanks for clarifying it.
diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h index ecefccbdf2e3..2de4d6e34b84 100644 --- a/arch/x86/include/asm/pgtable.h +++ b/arch/x86/include/asm/pgtable.h @@ -24,6 +24,7 @@ /* Make the page accesable by VMM for confidential guests */ #define pgprot_cc_guest(prot) __pgprot(pgprot_val(prot) | \ tdx_shared_mask()) +#define pgprot_cc_shared_mask() __pgprot(tdx_shared_mask()) #ifndef __ASSEMBLY__ #include <asm/x86_init.h> diff --git a/arch/x86/kernel/tdx.c b/arch/x86/kernel/tdx.c index c3e4cc5d631b..433f366ca25c 100644 --- a/arch/x86/kernel/tdx.c +++ b/arch/x86/kernel/tdx.c @@ -16,10 +16,16 @@ /* TDX Module call Leaf IDs */ #define TDX_GET_INFO 1 #define TDX_GET_VEINFO 3 +#define TDX_ACCEPT_PAGE 6 /* TDX hypercall Leaf IDs */ #define TDVMCALL_MAP_GPA 0x10001 +/* TDX Module call error codes */ +#define TDX_PAGE_ALREADY_ACCEPTED 0x00000b0a00000000 +#define TDCALL_RETURN_CODE_MASK 0xFFFFFFFF00000000 +#define TDCALL_RETURN_CODE(a) ((a) & TDCALL_RETURN_CODE_MASK) + #define VE_IS_IO_OUT(exit_qual) (((exit_qual) & 8) ? 0 : 1) #define VE_GET_IO_SIZE(exit_qual) (((exit_qual) & 7) + 1) #define VE_GET_PORT_NUM(exit_qual) ((exit_qual) >> 16) @@ -108,18 +114,35 @@ static void tdx_get_info(void) physical_mask &= ~tdx_shared_mask(); } +static void tdx_accept_page(phys_addr_t gpa) +{ + u64 ret; + + /* + * Pass the page physical address and size (0-4KB) to the + * TDX module to accept the pending, private page. More info + * about ABI can be found in TDX Guest-Host-Communication + * Interface (GHCI), sec 2.4.7. + */ + ret = __tdx_module_call(TDX_ACCEPT_PAGE, gpa, 0, 0, 0, NULL); + + /* + * Non zero return value means buggy TDX module (which is + * fatal for TDX guest). So panic here. + */ + BUG_ON(ret && TDCALL_RETURN_CODE(ret) != TDX_PAGE_ALREADY_ACCEPTED); +} + /* * Inform the VMM of the guest's intent for this physical page: * shared with the VMM or private to the guest. The VMM is * expected to change its mapping of the page in response. - * - * Note: shared->private conversions require further guest - * action to accept the page. */ int tdx_hcall_gpa_intent(phys_addr_t gpa, int numpages, enum tdx_map_type map_type) { - u64 ret; + u64 ret = 0; + int i; if (map_type == TDX_MAP_SHARED) gpa |= tdx_shared_mask(); @@ -131,8 +154,20 @@ int tdx_hcall_gpa_intent(phys_addr_t gpa, int numpages, */ ret = _tdx_hypercall(TDVMCALL_MAP_GPA, gpa, PAGE_SIZE * numpages, 0, 0, NULL); + if (ret) + ret = -EIO; + + if (ret || map_type == TDX_MAP_SHARED) + return ret; + + /* + * For shared->private conversion, accept the page using + * TDX_ACCEPT_PAGE TDX module call. + */ + for (i = 0; i < numpages; i++) + tdx_accept_page(gpa + i * PAGE_SIZE); - return ret ? -EIO : 0; + return 0; } static __cpuidle void _tdx_halt(const bool irq_disabled, const bool do_sti) diff --git a/arch/x86/mm/mem_encrypt_common.c b/arch/x86/mm/mem_encrypt_common.c index f063c885b0a5..119a9056efbb 100644 --- a/arch/x86/mm/mem_encrypt_common.c +++ b/arch/x86/mm/mem_encrypt_common.c @@ -9,9 +9,18 @@ #include <asm/mem_encrypt_common.h> #include <linux/dma-mapping.h> +#include <linux/cc_platform.h> /* Override for DMA direct allocation check - ARCH_HAS_FORCE_DMA_UNENCRYPTED */ bool force_dma_unencrypted(struct device *dev) { - return amd_force_dma_unencrypted(dev); + if (cc_platform_has(CC_ATTR_GUEST_TDX) && + cc_platform_has(CC_ATTR_GUEST_MEM_ENCRYPT)) + return true; + + if (cc_platform_has(CC_ATTR_GUEST_MEM_ENCRYPT) || + cc_platform_has(CC_ATTR_HOST_MEM_ENCRYPT)) + return amd_force_dma_unencrypted(dev); + + return false; } diff --git a/arch/x86/mm/pat/set_memory.c b/arch/x86/mm/pat/set_memory.c index 527957586f3c..6c531d5cb5fd 100644 --- a/arch/x86/mm/pat/set_memory.c +++ b/arch/x86/mm/pat/set_memory.c @@ -30,6 +30,7 @@ #include <asm/proto.h> #include <asm/memtype.h> #include <asm/set_memory.h> +#include <asm/tdx.h> #include "../mm_internal.h" @@ -1981,8 +1982,10 @@ int set_memory_global(unsigned long addr, int numpages) __pgprot(_PAGE_GLOBAL), 0); } -static int __set_memory_enc_dec(unsigned long addr, int numpages, bool enc) +static int __set_memory_protect(unsigned long addr, int numpages, bool protect) { + pgprot_t mem_protected_bits, mem_plain_bits; + enum tdx_map_type map_type; struct cpa_data cpa; int ret; @@ -1997,8 +2000,25 @@ static int __set_memory_enc_dec(unsigned long addr, int numpages, bool enc) memset(&cpa, 0, sizeof(cpa)); cpa.vaddr = &addr; cpa.numpages = numpages; - cpa.mask_set = enc ? __pgprot(_PAGE_ENC) : __pgprot(0); - cpa.mask_clr = enc ? __pgprot(0) : __pgprot(_PAGE_ENC); + + if (cc_platform_has(CC_ATTR_GUEST_SHARED_MAPPING_INIT)) { + mem_protected_bits = __pgprot(0); + mem_plain_bits = pgprot_cc_shared_mask(); + } else { + mem_protected_bits = __pgprot(_PAGE_ENC); + mem_plain_bits = __pgprot(0); + } + + if (protect) { + cpa.mask_set = mem_protected_bits; + cpa.mask_clr = mem_plain_bits; + map_type = TDX_MAP_PRIVATE; + } else { + cpa.mask_set = mem_plain_bits; + cpa.mask_clr = mem_protected_bits; + map_type = TDX_MAP_SHARED; + } + cpa.pgd = init_mm.pgd; /* Must avoid aliasing mappings in the highmem code */ @@ -2006,9 +2026,17 @@ static int __set_memory_enc_dec(unsigned long addr, int numpages, bool enc) vm_unmap_aliases(); /* - * Before changing the encryption attribute, we need to flush caches. + * Before changing the encryption attribute, flush caches. + * + * For TDX, guest is responsible for flushing caches on private->shared + * transition. VMM is responsible for flushing on shared->private. */ - cpa_flush(&cpa, !this_cpu_has(X86_FEATURE_SME_COHERENT)); + if (cc_platform_has(CC_ATTR_GUEST_TDX)) { + if (map_type == TDX_MAP_SHARED) + cpa_flush(&cpa, 1); + } else { + cpa_flush(&cpa, !this_cpu_has(X86_FEATURE_SME_COHERENT)); + } ret = __change_page_attr_set_clr(&cpa, 1); @@ -2021,18 +2049,21 @@ static int __set_memory_enc_dec(unsigned long addr, int numpages, bool enc) */ cpa_flush(&cpa, 0); + if (!ret && cc_platform_has(CC_ATTR_GUEST_SHARED_MAPPING_INIT)) + ret = tdx_hcall_gpa_intent(__pa(addr), numpages, map_type); + return ret; } int set_memory_encrypted(unsigned long addr, int numpages) { - return __set_memory_enc_dec(addr, numpages, true); + return __set_memory_protect(addr, numpages, true); } EXPORT_SYMBOL_GPL(set_memory_encrypted); int set_memory_decrypted(unsigned long addr, int numpages) { - return __set_memory_enc_dec(addr, numpages, false); + return __set_memory_protect(addr, numpages, false); } EXPORT_SYMBOL_GPL(set_memory_decrypted);