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b=b7PORn30pN8HsHARqBCTydwUAJ2/DumVIOmn2xqwnRgKspCf0HXQ0TiHtOmpOcHXiOVLoM4EMr29apIc5T2iiYT5icdN7qiFbZ3i3QXPYNz5gAceQG25wKHxp7dO+fUiIxrkwfctzgWEvUgbr3N861ThDHKlRhqTmM+0O8jBL8I= Authentication-Results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=amd.com; Received: from BL3PR12MB9049.namprd12.prod.outlook.com (2603:10b6:208:3b8::21) by BL3PR12MB6426.namprd12.prod.outlook.com (2603:10b6:208:3b5::12) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.8655.35; Thu, 24 Apr 2025 19:27:48 +0000 Received: from BL3PR12MB9049.namprd12.prod.outlook.com ([fe80::c170:6906:9ef3:ecef]) by BL3PR12MB9049.namprd12.prod.outlook.com ([fe80::c170:6906:9ef3:ecef%5]) with mapi id 15.20.8655.033; Thu, 24 Apr 2025 19:27:48 +0000 Message-ID: <0238d607-3fd7-4deb-92ac-c01aca2090fa@amd.com> Date: Thu, 24 Apr 2025 14:27:44 -0500 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] x86/sev: Fix making shared pages private during kdump To: Tom Lendacky , tglx@linutronix.de, mingo@redhat.com, dave.hansen@linux.intel.com, x86@kernel.org, bp@alien8.de, hpa@zytor.com Cc: michael.roth@amd.com, nikunj@amd.com, seanjc@google.com, ardb@kernel.org, stable@vger.kernel.org, linux-kernel@vger.kernel.org, kexec@lists.infradead.org, linux-coco@lists.linux.dev References: <20250424142739.673666-1-Ashish.Kalra@amd.com> <4311dbc7-efb5-ab6e-046c-87e833119236@amd.com> Content-Language: en-US From: "Kalra, Ashish" In-Reply-To: <4311dbc7-efb5-ab6e-046c-87e833119236@amd.com> Content-Type: text/plain; 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>> ghcb = (unsigned long)&data->ghcb_page; >> >> - if (addr <= ghcb && ghcb <= addr + size) { >> + /* Handle the case of 2MB page containing the GHCB page */ > > s/2MB page/a huge page/ > >> + if (level == PG_LEVEL_4K && addr == ghcb) { >> + skipped_addr = true; >> + break; >> + } >> + if (level > PG_LEVEL_4K && addr <= ghcb && >> + ghcb < addr + size) { >> skipped_addr = true; >> break; >> } >> @@ -1106,6 +1112,9 @@ void snp_kexec_finish(void) >> ghcb = &data->ghcb_page; >> pte = lookup_address((unsigned long)ghcb, &level); >> size = page_level_size(level); >> + /* Handle the case of 2MB page containing the GHCB page */ >> + if (level > PG_LEVEL_4K) >> + ghcb = (struct ghcb *)((unsigned long)ghcb & PMD_MASK); > > For safety, shouldn't the mask be based on the level/size that is returned? > Yes that makes sense and i will fix it accordingly. Thanks, Ashish > Thanks, > Tom > >> set_pte_enc(pte, level, (void *)ghcb); >> snp_set_memory_private((unsigned long)ghcb, (size / PAGE_SIZE)); >> }