From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail.skyhub.de (mail.skyhub.de [5.9.137.197]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 0693C72 for ; Fri, 24 Sep 2021 14:04:15 +0000 (UTC) Received: from zn.tnic (p200300ec2f0dd6008eddcbd152a1c1b1.dip0.t-ipconnect.de [IPv6:2003:ec:2f0d:d600:8edd:cbd1:52a1:c1b1]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.skyhub.de (SuperMail on ZX Spectrum 128k) with ESMTPSA id 0122D1EC0541; Fri, 24 Sep 2021 16:04:08 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=alien8.de; s=dkim; t=1632492249; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:in-reply-to:in-reply-to: references:references; bh=HHrCbHtfMapdgdHCywxiLt5xWw+NugbzfPjFHMI1IsA=; b=izZgEa0Nz5w/sF+dYGp81sHbvdgjXfqEv4hReEWlibBKbHN5yf3biZcl359Jjb8C1slTp2 9TCezwSIRcGAgAdIIzYHCFDPGt0B7TGKaK37szg8jY+26PmviIwjwYRDRmg6QfSXtWTAiP 2U9NKFoADRHb0CpQ/y1xb1NeV2e/FGg= Date: Fri, 24 Sep 2021 16:04:00 +0200 From: Borislav Petkov To: Brijesh Singh Cc: x86@kernel.org, linux-kernel@vger.kernel.org, kvm@vger.kernel.org, linux-coco@lists.linux.dev, linux-mm@kvack.org, linux-crypto@vger.kernel.org, Thomas Gleixner , Ingo Molnar , Joerg Roedel , Tom Lendacky , "H. Peter Anvin" , Ard Biesheuvel , Paolo Bonzini , Sean Christopherson , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Andy Lutomirski , Dave Hansen , Sergio Lopez , Peter Gonda , Peter Zijlstra , Srinivas Pandruvada , David Rientjes , Dov Murik , Tobin Feldman-Fitzthum , Michael Roth , Vlastimil Babka , "Kirill A . Shutemov" , Andi Kleen , tony.luck@intel.com, marcorr@google.com, sathyanarayanan.kuppuswamy@linux.intel.com Subject: Re: [PATCH Part2 v5 05/45] x86/sev: Add helper functions for RMPUPDATE and PSMASH instruction Message-ID: References: <20210820155918.7518-1-brijesh.singh@amd.com> <20210820155918.7518-6-brijesh.singh@amd.com> Precedence: bulk X-Mailing-List: linux-coco@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20210820155918.7518-6-brijesh.singh@amd.com> On Fri, Aug 20, 2021 at 10:58:38AM -0500, Brijesh Singh wrote: > The RMPUPDATE instruction writes a new RMP entry in the RMP Table. The > hypervisor will use the instruction to add pages to the RMP table. See > APM3 for details on the instruction operations. > > The PSMASH instruction expands a 2MB RMP entry into a corresponding set of > contiguous 4KB-Page RMP entries. The hypervisor will use this instruction > to adjust the RMP entry without invalidating the previous RMP entry. > > Signed-off-by: Brijesh Singh > --- > arch/x86/include/asm/sev.h | 11 ++++++ > arch/x86/kernel/sev.c | 72 ++++++++++++++++++++++++++++++++++++++ > 2 files changed, 83 insertions(+) > > diff --git a/arch/x86/include/asm/sev.h b/arch/x86/include/asm/sev.h > index 5b1a6a075c47..92ced9626e95 100644 > --- a/arch/x86/include/asm/sev.h > +++ b/arch/x86/include/asm/sev.h > @@ -78,7 +78,9 @@ extern bool handle_vc_boot_ghcb(struct pt_regs *regs); > > /* RMP page size */ > #define RMP_PG_SIZE_4K 0 > +#define RMP_PG_SIZE_2M 1 > #define RMP_TO_X86_PG_LEVEL(level) (((level) == RMP_PG_SIZE_4K) ? PG_LEVEL_4K : PG_LEVEL_2M) > +#define X86_TO_RMP_PG_LEVEL(level) (((level) == PG_LEVEL_4K) ? RMP_PG_SIZE_4K : RMP_PG_SIZE_2M) > > /* > * The RMP entry format is not architectural. The format is defined in PPR > @@ -107,6 +109,15 @@ struct __packed rmpentry { > > #define RMPADJUST_VMSA_PAGE_BIT BIT(16) > > +struct rmpupdate { Function is called the same way - maybe this should be called rmpupdate_desc or so. > + u64 gpa; > + u8 assigned; > + u8 pagesize; > + u8 immutable; > + u8 rsvd; > + u32 asid; > +} __packed; > + > #ifdef CONFIG_AMD_MEM_ENCRYPT > extern struct static_key_false sev_es_enable_key; > extern void __sev_es_ist_enter(struct pt_regs *regs); > diff --git a/arch/x86/kernel/sev.c b/arch/x86/kernel/sev.c > index f383d2a89263..8627c49666c9 100644 > --- a/arch/x86/kernel/sev.c > +++ b/arch/x86/kernel/sev.c > @@ -2419,3 +2419,75 @@ int snp_lookup_rmpentry(u64 pfn, int *level) > return !!rmpentry_assigned(e); > } > EXPORT_SYMBOL_GPL(snp_lookup_rmpentry); > + <--- kernel-doc comment. > +int psmash(u64 pfn) > +{ > + unsigned long paddr = pfn << PAGE_SHIFT; > + int ret; > + > + if (!pfn_valid(pfn)) > + return -EINVAL; > + > + if (!cpu_feature_enabled(X86_FEATURE_SEV_SNP)) > + return -ENXIO; Make that the first check pls. > + > + /* Binutils version 2.36 supports the PSMASH mnemonic. */ > + asm volatile(".byte 0xF3, 0x0F, 0x01, 0xFF" > + : "=a"(ret) > + : "a"(paddr) > + : "memory", "cc"); > + > + return ret; > +} > +EXPORT_SYMBOL_GPL(psmash); That's for kvm? > +static int rmpupdate(u64 pfn, struct rmpupdate *val) > +{ > + unsigned long paddr = pfn << PAGE_SHIFT; > + int ret; > + > + if (!pfn_valid(pfn)) > + return -EINVAL; > + > + if (!cpu_feature_enabled(X86_FEATURE_SEV_SNP)) > + return -ENXIO; Also first check. > + > + /* Binutils version 2.36 supports the RMPUPDATE mnemonic. */ > + asm volatile(".byte 0xF2, 0x0F, 0x01, 0xFE" > + : "=a"(ret) > + : "a"(paddr), "c"((unsigned long)val) > + : "memory", "cc"); > + return ret; > +} > + > +int rmp_make_private(u64 pfn, u64 gpa, enum pg_level level, int asid, bool immutable) > +{ > + struct rmpupdate val; > + > + if (!pfn_valid(pfn)) > + return -EINVAL; rmpupdate() does that check too so choose one place please and kill the other. > + memset(&val, 0, sizeof(val)); > + val.assigned = 1; > + val.asid = asid; > + val.immutable = immutable; > + val.gpa = gpa; > + val.pagesize = X86_TO_RMP_PG_LEVEL(level); > + > + return rmpupdate(pfn, &val); > +} > +EXPORT_SYMBOL_GPL(rmp_make_private); > + > +int rmp_make_shared(u64 pfn, enum pg_level level) > +{ > + struct rmpupdate val; > + > + if (!pfn_valid(pfn)) > + return -EINVAL; > + > + memset(&val, 0, sizeof(val)); > + val.pagesize = X86_TO_RMP_PG_LEVEL(level); > + > + return rmpupdate(pfn, &val); > +} > +EXPORT_SYMBOL_GPL(rmp_make_shared); Both exports for kvm I assume? Thx. -- Regards/Gruss, Boris. https://people.kernel.org/tglx/notes-about-netiquette