From: Brijesh Singh <Brijesh.Singh@xxxxxxx> Invoke a hypercall when a memory region is changed from encrypted -> decrypted and vice versa. Hypervisor need to know the page encryption status during the guest migration. Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Cc: Ingo Molnar <mingo@xxxxxxxxxx> Cc: "H. Peter Anvin" <hpa@xxxxxxxxx> Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx> Cc: "Radim Krčmář" <rkrcmar@xxxxxxxxxx> Cc: Joerg Roedel <joro@xxxxxxxxxx> Cc: Borislav Petkov <bp@xxxxxxx> Cc: Tom Lendacky <thomas.lendacky@xxxxxxx> Cc: x86@xxxxxxxxxx Cc: kvm@xxxxxxxxxxxxxxx Cc: linux-kernel@xxxxxxxxxxxxxxx Signed-off-by: Brijesh Singh <brijesh.singh@xxxxxxx> Signed-off-by: Ashish Kalra <ashish.kalra@xxxxxxx> --- arch/x86/include/asm/paravirt.h | 10 +++++ arch/x86/include/asm/paravirt_types.h | 2 + arch/x86/kernel/paravirt.c | 1 + arch/x86/mm/mem_encrypt.c | 57 ++++++++++++++++++++++++++- arch/x86/mm/pat/set_memory.c | 7 ++++ 5 files changed, 76 insertions(+), 1 deletion(-) diff --git a/arch/x86/include/asm/paravirt.h b/arch/x86/include/asm/paravirt.h index 694d8daf4983..8127b9c141bf 100644 --- a/arch/x86/include/asm/paravirt.h +++ b/arch/x86/include/asm/paravirt.h @@ -78,6 +78,12 @@ static inline void paravirt_arch_exit_mmap(struct mm_struct *mm) PVOP_VCALL1(mmu.exit_mmap, mm); } +static inline void page_encryption_changed(unsigned long vaddr, int npages, + bool enc) +{ + PVOP_VCALL3(mmu.page_encryption_changed, vaddr, npages, enc); +} + #ifdef CONFIG_PARAVIRT_XXL static inline void load_sp0(unsigned long sp0) { @@ -946,6 +952,10 @@ static inline void paravirt_arch_dup_mmap(struct mm_struct *oldmm, static inline void paravirt_arch_exit_mmap(struct mm_struct *mm) { } + +static inline void page_encryption_changed(unsigned long vaddr, int npages, bool enc) +{ +} #endif #endif /* __ASSEMBLY__ */ #endif /* _ASM_X86_PARAVIRT_H */ diff --git a/arch/x86/include/asm/paravirt_types.h b/arch/x86/include/asm/paravirt_types.h index 732f62e04ddb..03bfd515c59c 100644 --- a/arch/x86/include/asm/paravirt_types.h +++ b/arch/x86/include/asm/paravirt_types.h @@ -215,6 +215,8 @@ struct pv_mmu_ops { /* Hook for intercepting the destruction of an mm_struct. */ void (*exit_mmap)(struct mm_struct *mm); + void (*page_encryption_changed)(unsigned long vaddr, int npages, + bool enc); #ifdef CONFIG_PARAVIRT_XXL struct paravirt_callee_save read_cr2; diff --git a/arch/x86/kernel/paravirt.c b/arch/x86/kernel/paravirt.c index c131ba4e70ef..840c02b23aeb 100644 --- a/arch/x86/kernel/paravirt.c +++ b/arch/x86/kernel/paravirt.c @@ -367,6 +367,7 @@ struct paravirt_patch_template pv_ops = { (void (*)(struct mmu_gather *, void *))tlb_remove_page, .mmu.exit_mmap = paravirt_nop, + .mmu.page_encryption_changed = paravirt_nop, #ifdef CONFIG_PARAVIRT_XXL .mmu.read_cr2 = __PV_IS_CALLEE_SAVE(native_read_cr2), diff --git a/arch/x86/mm/mem_encrypt.c b/arch/x86/mm/mem_encrypt.c index f4bd4b431ba1..c9800fa811f6 100644 --- a/arch/x86/mm/mem_encrypt.c +++ b/arch/x86/mm/mem_encrypt.c @@ -19,6 +19,7 @@ #include <linux/kernel.h> #include <linux/bitops.h> #include <linux/dma-mapping.h> +#include <linux/kvm_para.h> #include <asm/tlbflush.h> #include <asm/fixmap.h> @@ -29,6 +30,7 @@ #include <asm/processor-flags.h> #include <asm/msr.h> #include <asm/cmdline.h> +#include <asm/kvm_para.h> #include "mm_internal.h" @@ -196,6 +198,47 @@ void __init sme_early_init(void) swiotlb_force = SWIOTLB_FORCE; } +static void set_memory_enc_dec_hypercall(unsigned long vaddr, int npages, + bool enc) +{ + unsigned long sz = npages << PAGE_SHIFT; + unsigned long vaddr_end, vaddr_next; + + vaddr_end = vaddr + sz; + + for (; vaddr < vaddr_end; vaddr = vaddr_next) { + int psize, pmask, level; + unsigned long pfn; + pte_t *kpte; + + kpte = lookup_address(vaddr, &level); + if (!kpte || pte_none(*kpte)) + return; + + switch (level) { + case PG_LEVEL_4K: + pfn = pte_pfn(*kpte); + break; + case PG_LEVEL_2M: + pfn = pmd_pfn(*(pmd_t *)kpte); + break; + case PG_LEVEL_1G: + pfn = pud_pfn(*(pud_t *)kpte); + break; + default: + return; + } + + psize = page_level_size(level); + pmask = page_level_mask(level); + + kvm_sev_hypercall3(KVM_HC_PAGE_ENC_STATUS, + pfn << PAGE_SHIFT, psize >> PAGE_SHIFT, enc); + + vaddr_next = (vaddr & pmask) + psize; + } +} + static void __init __set_clr_pte_enc(pte_t *kpte, int level, bool enc) { pgprot_t old_prot, new_prot; @@ -253,12 +296,13 @@ static void __init __set_clr_pte_enc(pte_t *kpte, int level, bool enc) static int __init early_set_memory_enc_dec(unsigned long vaddr, unsigned long size, bool enc) { - unsigned long vaddr_end, vaddr_next; + unsigned long vaddr_end, vaddr_next, start; unsigned long psize, pmask; int split_page_size_mask; int level, ret; pte_t *kpte; + start = vaddr; vaddr_next = vaddr; vaddr_end = vaddr + size; @@ -313,6 +357,8 @@ static int __init early_set_memory_enc_dec(unsigned long vaddr, ret = 0; + set_memory_enc_dec_hypercall(start, PAGE_ALIGN(size) >> PAGE_SHIFT, + enc); out: __flush_tlb_all(); return ret; @@ -451,6 +497,15 @@ void __init mem_encrypt_init(void) if (sev_active()) static_branch_enable(&sev_enable_key); +#ifdef CONFIG_PARAVIRT + /* + * With SEV, we need to make a hypercall when page encryption state is + * changed. + */ + if (sev_active()) + pv_ops.mmu.page_encryption_changed = set_memory_enc_dec_hypercall; +#endif + pr_info("AMD %s active\n", sev_active() ? "Secure Encrypted Virtualization (SEV)" : "Secure Memory Encryption (SME)"); diff --git a/arch/x86/mm/pat/set_memory.c b/arch/x86/mm/pat/set_memory.c index c4aedd00c1ba..86b7804129fc 100644 --- a/arch/x86/mm/pat/set_memory.c +++ b/arch/x86/mm/pat/set_memory.c @@ -26,6 +26,7 @@ #include <asm/proto.h> #include <asm/memtype.h> #include <asm/set_memory.h> +#include <asm/paravirt.h> #include "../mm_internal.h" @@ -1987,6 +1988,12 @@ static int __set_memory_enc_dec(unsigned long addr, int numpages, bool enc) */ cpa_flush(&cpa, 0); + /* Notify hypervisor that a given memory range is mapped encrypted + * or decrypted. The hypervisor will use this information during the + * VM migration. + */ + page_encryption_changed(addr, numpages, enc); + return ret; } -- 2.17.1