From: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx> [ Upstream commit 3f6819dd192ef4f0c568ec3e9d6d408b3fa1ad3d ] TDX code is going to provide guest.enc_status_change_prepare() that is able to fail. TDX will use the call to convert the GPA range from shared to private. This operation can fail. Add a way to return an error from the callback. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx> Signed-off-by: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx> Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@xxxxxxxxxxxxxxx> Link: https://lore.kernel.org/all/20230606095622.1939-2-kirill.shutemov%40linux.intel.com Stable-dep-of: 195edce08b63 ("x86/tdx: Fix race between set_memory_encrypted() and load_unaligned_zeropad()") Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- arch/x86/include/asm/x86_init.h | 2 +- arch/x86/kernel/x86_init.c | 2 +- arch/x86/mm/mem_encrypt_amd.c | 4 +++- arch/x86/mm/pat/set_memory.c | 3 ++- 4 files changed, 7 insertions(+), 4 deletions(-) diff --git a/arch/x86/include/asm/x86_init.h b/arch/x86/include/asm/x86_init.h index 88085f369ff6f..1ca9701917c55 100644 --- a/arch/x86/include/asm/x86_init.h +++ b/arch/x86/include/asm/x86_init.h @@ -150,7 +150,7 @@ struct x86_init_acpi { * @enc_cache_flush_required Returns true if a cache flush is needed before changing page encryption status */ struct x86_guest { - void (*enc_status_change_prepare)(unsigned long vaddr, int npages, bool enc); + bool (*enc_status_change_prepare)(unsigned long vaddr, int npages, bool enc); bool (*enc_status_change_finish)(unsigned long vaddr, int npages, bool enc); bool (*enc_tlb_flush_required)(bool enc); bool (*enc_cache_flush_required)(void); diff --git a/arch/x86/kernel/x86_init.c b/arch/x86/kernel/x86_init.c index d82f4fa2f1bfe..f230d4d7d8eb4 100644 --- a/arch/x86/kernel/x86_init.c +++ b/arch/x86/kernel/x86_init.c @@ -130,7 +130,7 @@ struct x86_cpuinit_ops x86_cpuinit = { static void default_nmi_init(void) { }; -static void enc_status_change_prepare_noop(unsigned long vaddr, int npages, bool enc) { } +static bool enc_status_change_prepare_noop(unsigned long vaddr, int npages, bool enc) { return true; } static bool enc_status_change_finish_noop(unsigned long vaddr, int npages, bool enc) { return false; } static bool enc_tlb_flush_required_noop(bool enc) { return false; } static bool enc_cache_flush_required_noop(void) { return false; } diff --git a/arch/x86/mm/mem_encrypt_amd.c b/arch/x86/mm/mem_encrypt_amd.c index e0b51c09109f6..4f95c449a406e 100644 --- a/arch/x86/mm/mem_encrypt_amd.c +++ b/arch/x86/mm/mem_encrypt_amd.c @@ -319,7 +319,7 @@ static void enc_dec_hypercall(unsigned long vaddr, int npages, bool enc) #endif } -static void amd_enc_status_change_prepare(unsigned long vaddr, int npages, bool enc) +static bool amd_enc_status_change_prepare(unsigned long vaddr, int npages, bool enc) { /* * To maintain the security guarantees of SEV-SNP guests, make sure @@ -327,6 +327,8 @@ static void amd_enc_status_change_prepare(unsigned long vaddr, int npages, bool */ if (cc_platform_has(CC_ATTR_GUEST_SEV_SNP) && !enc) snp_set_memory_shared(vaddr, npages); + + return true; } /* Return true unconditionally: return value doesn't matter for the SEV side */ diff --git a/arch/x86/mm/pat/set_memory.c b/arch/x86/mm/pat/set_memory.c index 7159cf7876130..b8f48ebe753c7 100644 --- a/arch/x86/mm/pat/set_memory.c +++ b/arch/x86/mm/pat/set_memory.c @@ -2151,7 +2151,8 @@ static int __set_memory_enc_pgtable(unsigned long addr, int numpages, bool enc) cpa_flush(&cpa, x86_platform.guest.enc_cache_flush_required()); /* Notify hypervisor that we are about to set/clr encryption attribute. */ - x86_platform.guest.enc_status_change_prepare(addr, numpages, enc); + if (!x86_platform.guest.enc_status_change_prepare(addr, numpages, enc)) + return -EIO; ret = __change_page_attr_set_clr(&cpa, 1); -- 2.39.2
