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(c-67-170-100-148.hsd1.wa.comcast.net [67.170.100.148]) by linux.microsoft.com (Postfix) with ESMTPSA id 688C3212C81A; Mon, 25 Sep 2023 14:28:29 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 688C3212C81A DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1695677310; bh=cAGeMcIZ4Qy0IHeYwlwP8jAIbqxHmBYRtqsMcKGODxQ=; h=Subject:From:To:Date:In-Reply-To:References:From; b=eeABRksv2rgxphiy5aAtajUIWfiwgwwfYye3Vr4ps/z99Y0+or0qxklh853TE4TY7 37qcOwLdLDeWd4gY4i3IdH+xQgGH95kd88lWQDlYrNDpxte+COS/ViuYl5cpC/wXp5 sZ43Xtu3jonbzYFtmMPptwgvVzMMky9ZnIYc1jwA= Subject: [RFC PATCH v2 7/7] Drivers: hv: Allocate persistent pages for root partition From: Stanislav Kinsburskii To: tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, x86@kernel.org, hpa@zytor.com, ebiederm@xmission.com, akpm@linux-foundation.org, stanislav.kinsburskii@gmail.com, corbet@lwn.net, linux-kernel@vger.kernel.org, kexec@lists.infradead.org, linux-mm@kvack.org, kys@microsoft.com, jgowans@amazon.com, wei.liu@kernel.org, arnd@arndb.de, gregkh@linuxfoundation.org, graf@amazon.de, pbonzini@redhat.com Date: Mon, 25 Sep 2023 14:28:28 -0700 Message-ID: <169567730882.19708.11955721929072363659.stgit@skinsburskii.> In-Reply-To: <169567722094.19708.3583735425859054859.stgit@skinsburskii.> References: <169567722094.19708.3583735425859054859.stgit@skinsburskii.> User-Agent: StGit/0.19 MIME-Version: 1.0 X-Rspamd-Queue-Id: C0B4040008 X-Rspam-User: X-Rspamd-Server: rspam02 X-Stat-Signature: kq7sq4sord1xxz5zatbho6i98dczjx4e X-HE-Tag: 1695677310-116012 X-HE-Meta: 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 k889eFa4 s6wdrXUNB6tTRRpKx0oxK6FY7A65yC5MJRQ748rLuymgqGxseCInQD04Qz8GioDsKJL9OQIvuXMa1ys1Sc2Uu9hQ1spARf5D2fbRDNcuFiMD4XgZcCp8xeGhWdSG0TRN2RdsCg0g6yNqSbXF6CKiym/WiVqRaDKtYNFLIXaxn4TE4caQAFfABrqN/SWjT0EQsTGDyTwwkPElMf33eQ5jvNWnkyINj8arQI/PoRddzTc6I3eDLl8zWG3C+fooTKSYt7kE8Dw8ECgfYhQKcIQY5rVJ0cA== X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: Deposited pages are owned by the hypervisor. Accessing them can trigger a kernel panic due to a general protection fault. This patch ensures that pages for the root partition are allocated from the persistent memory pool. This allocation guarantees stability post-kexec, protecting hypervisor-deposited pages from unintended reuse by the new kernel. Signed-off-by: Stanislav Kinsburskii --- drivers/hv/hv_common.c | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-) diff --git a/drivers/hv/hv_common.c b/drivers/hv/hv_common.c index 335aec5ec504..a81c5613e745 100644 --- a/drivers/hv/hv_common.c +++ b/drivers/hv/hv_common.c @@ -426,7 +426,10 @@ int hv_call_deposit_pages(int node, u64 partition_id, u32 num_pages) order = 31 - __builtin_clz(num_pages); while (1) { - pages[i] = alloc_pages_node(node, GFP_KERNEL, order); + if (paritition_id == hv_current_partition_id) + pages[i] = pmpool_alloc(1 << order); + else + pages[i] = alloc_pages_node(node, GFP_KERNEL, order); if (pages[i]) break; if (!order) { @@ -471,8 +474,12 @@ int hv_call_deposit_pages(int node, u64 partition_id, u32 num_pages) err_free_allocations: for (i = 0; i < num_allocations; ++i) { base_pfn = page_to_pfn(pages[i]); - for (j = 0; j < counts[i]; ++j) - __free_page(pfn_to_page(base_pfn + j)); + for (j = 0; j < counts[i]; ++j) { + if (paritition_id == hv_current_partition_id) + pmpool_release(pages[i], counts[i]); + else + __free_page(pfn_to_page(base_pfn + j)); + } } free_buf: