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[209.132.180.67]) by mx.google.com with ESMTP id 109si4401104otv.36.2020.04.03.14.09.48; Fri, 03 Apr 2020 14:10:01 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; dkim=pass header.i=@oracle.com header.s=corp-2020-01-29 header.b=ToYaSMcD; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=oracle.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728368AbgDCVJ3 (ORCPT + 99 others); Fri, 3 Apr 2020 17:09:29 -0400 Received: from userp2130.oracle.com ([156.151.31.86]:50752 "EHLO userp2130.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727829AbgDCVJ3 (ORCPT ); Fri, 3 Apr 2020 17:09:29 -0400 Received: from pps.filterd (userp2130.oracle.com [127.0.0.1]) by userp2130.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 033L7vn8015410; Fri, 3 Apr 2020 21:09:07 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=subject : to : cc : references : from : message-id : date : mime-version : in-reply-to : content-type : content-transfer-encoding; s=corp-2020-01-29; bh=Zi65tcjdHpPyPnpZ89iL9X+3dDG5TYStO2MVa6Ry6zI=; b=ToYaSMcDrXt1+y9IJvf5tkwMTG7cMn+ZuyH8R4urFVjHhQCqOp4mPEMKYmogmz3jWliP PXoManGO3ow+RyoCMtAhvExJZFaWl93DLEcuy4laiG1qzpqo29K2j+YSNiOdZswsnTIv Bw0Ytv+PHtOsqKS1csjXA1U4pPFbXJLB5yXMy/jpUVF6ih7ZlMWYTU5Zwq8MeBPQHUVB RamvUO3eddkX4wyIu3+TmqAt30o5CZ4/IGvv/e28gZi6sd4WzWBRRZp2jM31DnJgtEpv sl1ztSgFr8p9h7lV/t3zx4Kh2IG/kNGzah10bdHuYx8bdrdGFtdl7hZiLHvDORZfugO9 zA== Received: from aserp3030.oracle.com (aserp3030.oracle.com [141.146.126.71]) by userp2130.oracle.com with ESMTP id 303cevk7k0-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 03 Apr 2020 21:09:06 +0000 Received: from pps.filterd (aserp3030.oracle.com [127.0.0.1]) by aserp3030.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 033L6Pjh144862; Fri, 3 Apr 2020 21:07:06 GMT Received: from aserv0122.oracle.com (aserv0122.oracle.com [141.146.126.236]) by aserp3030.oracle.com with ESMTP id 302g4y6qq0-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 03 Apr 2020 21:07:06 +0000 Received: from abhmp0011.oracle.com (abhmp0011.oracle.com [141.146.116.17]) by aserv0122.oracle.com (8.14.4/8.14.4) with ESMTP id 033L74n6004609; Fri, 3 Apr 2020 21:07:05 GMT Received: from localhost.localdomain (/10.159.159.117) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Fri, 03 Apr 2020 21:07:04 +0000 Subject: Re: [PATCH v6 10/14] mm: x86: Invoke hypercall when page encryption status is changed To: Ashish Kalra , pbonzini@redhat.com Cc: tglx@linutronix.de, mingo@redhat.com, hpa@zytor.com, joro@8bytes.org, bp@suse.de, thomas.lendacky@amd.com, x86@kernel.org, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, rientjes@google.com, srutherford@google.com, luto@kernel.org, brijesh.singh@amd.com References: <05c9015fb13b25c07a84d5638a7cd65a8c136cf0.1585548051.git.ashish.kalra@amd.com> From: Krish Sadhukhan Message-ID: <4021365b-c43a-02ae-475c-626199c8c451@oracle.com> Date: Fri, 3 Apr 2020 14:07:02 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.7.0 MIME-Version: 1.0 In-Reply-To: <05c9015fb13b25c07a84d5638a7cd65a8c136cf0.1585548051.git.ashish.kalra@amd.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Content-Language: en-US X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9580 signatures=668685 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 adultscore=0 bulkscore=0 suspectscore=0 mlxscore=0 spamscore=0 malwarescore=0 mlxlogscore=999 phishscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2003020000 definitions=main-2004030166 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9580 signatures=668685 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 priorityscore=1501 adultscore=0 clxscore=1015 phishscore=0 lowpriorityscore=0 spamscore=0 malwarescore=0 suspectscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2003020000 definitions=main-2004030166 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 3/29/20 11:22 PM, Ashish Kalra wrote: > From: Brijesh Singh > > 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 > Cc: Ingo Molnar > Cc: "H. Peter Anvin" > Cc: Paolo Bonzini > Cc: "Radim Krčmář" > Cc: Joerg Roedel > Cc: Borislav Petkov > Cc: Tom Lendacky > Cc: x86@kernel.org > Cc: kvm@vger.kernel.org > Cc: linux-kernel@vger.kernel.org > Signed-off-by: Brijesh Singh > Signed-off-by: Ashish Kalra > --- > 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 > #include > #include > +#include > > #include > #include > @@ -29,6 +30,7 @@ > #include > #include > #include > +#include > > #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; > + } Is it possible to re-use the code in __set_clr_pte_enc() ? > + > + 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); If I haven't missed anything, it seems early_set_memory_encrypted() doesn't have a caller. So is there a possibility that we can end up calling it in non-SEV context and hence do we need to have the sev_active() guard here ? > 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 > #include > #include > +#include > > #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; > } >