From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from firstgate.proxmox.com (firstgate.proxmox.com [212.224.123.68]) by lore.proxmox.com (Postfix) with ESMTPS id 2E0CB1FF56B for ; Mon, 22 Apr 2024 14:16:34 +0200 (CEST) Received: from firstgate.proxmox.com (localhost [127.0.0.1]) by firstgate.proxmox.com (Proxmox) with ESMTP id E61C2105D4; Mon, 22 Apr 2024 14:16:37 +0200 (CEST) From: Markus Frank To: pve-devel@lists.proxmox.com Date: Mon, 22 Apr 2024 14:16:15 +0200 Message-Id: <20240422121617.1131803-1-m.frank@proxmox.com> X-Mailer: git-send-email 2.39.2 MIME-Version: 1.0 X-SPAM-LEVEL: Spam detection results: 0 AWL -0.081 Adjusted score from AWL reputation of From: address BAYES_00 -1.9 Bayes spam probability is 0 to 1% DMARC_MISSING 0.1 Missing DMARC policy KAM_DMARC_STATUS 0.01 Test Rule for DKIM or SPF Failure with Strict Alignment PROLO_LEO1 0.1 Meta Catches all Leo drug variations so far SPF_HELO_NONE 0.001 SPF: HELO does not publish an SPF Record SPF_PASS -0.001 SPF: sender matches SPF record Subject: [pve-devel] [PATCH qemu-server v7 1/3] add C program to get AMD SEV hardware parameters from CPUID X-BeenThere: pve-devel@lists.proxmox.com X-Mailman-Version: 2.1.29 Precedence: list List-Id: Proxmox VE development discussion List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: Proxmox VE development discussion Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: pve-devel-bounces@lists.proxmox.com Sender: "pve-devel" Implement a systemd service that runs a C program that extracts AMD SEV hardware parameters such as reduced-phys-bios and cbitpos from CPUID at boot time, looks if SEV, SEV-ES & SEV-SNP are enabled, and outputs these details as JSON to /run/qemu-server/hw-params.json. This programm can also be used to read and save other hardware information at boot time. Signed-off-by: Markus Frank Co-authored-by: Thomas Lamprecht --- v7: * renamed amd-sev-support to query-machine-params * mv /run/amd-sev-params to /run/qemu-server/hw-params.json * add "mkdir /run/qemu-server" to ensure that the directory exists * moved json content to amd-sev property inside a bigger json so that other hardware parameters could also be read at boot time and included in this json file. Makefile | 1 + query-machine-params/Makefile | 21 +++++++ query-machine-params/query-machine-params.c | 55 +++++++++++++++++++ .../query-machine-params.service | 12 ++++ 4 files changed, 89 insertions(+) create mode 100644 query-machine-params/Makefile create mode 100644 query-machine-params/query-machine-params.c create mode 100644 query-machine-params/query-machine-params.service diff --git a/Makefile b/Makefile index 133468d..de32036 100644 --- a/Makefile +++ b/Makefile @@ -65,6 +65,7 @@ install: $(PKGSOURCES) install -m 0644 -D bootsplash.jpg $(DESTDIR)/usr/share/$(PACKAGE) $(MAKE) -C PVE install $(MAKE) -C qmeventd install + $(MAKE) -C query-machine-params install $(MAKE) -C qemu-configs install $(MAKE) -C vm-network-scripts install install -m 0755 qm $(DESTDIR)$(SBINDIR) diff --git a/query-machine-params/Makefile b/query-machine-params/Makefile new file mode 100644 index 0000000..e657bd1 --- /dev/null +++ b/query-machine-params/Makefile @@ -0,0 +1,21 @@ +DESTDIR= +PREFIX=/usr +SBINDIR=${PREFIX}/libexec/qemu-server +SERVICEDIR=/lib/systemd/system + +CC ?= gcc +CFLAGS += -O2 -fanalyzer -Werror -Wall -Wextra -Wpedantic -Wtype-limits -Wl,-z,relro -std=gnu11 + +query-machine-params: query-machine-params.c + $(CC) $(CFLAGS) -o $@ $< $(LDFLAGS) + +.PHONY: install +install: query-machine-params + install -d ${DESTDIR}/${SBINDIR} + install -d ${DESTDIR}${SERVICEDIR} + install -m 0644 query-machine-params.service ${DESTDIR}${SERVICEDIR} + install -m 0755 query-machine-params ${DESTDIR}${SBINDIR} + +.PHONY: clean +clean: + rm -f query-machine-params diff --git a/query-machine-params/query-machine-params.c b/query-machine-params/query-machine-params.c new file mode 100644 index 0000000..9552347 --- /dev/null +++ b/query-machine-params/query-machine-params.c @@ -0,0 +1,55 @@ +#include +#include +#include +#include +#include + +int main() { + uint32_t eax, ebx, ecx, edx; + + // query Encrypted Memory Capabilities, see: + // https://en.wikipedia.org/wiki/CPUID#EAX=8000001Fh:_Encrypted_Memory_Capabilities + uint32_t query_function = 0x8000001F; + asm volatile("cpuid" + : "=a"(eax), "=b"(ebx), "=c"(ecx), "=d"(edx) + : "0"(query_function) + ); + + bool sev_support = (eax & (1<<1)) != 0; + bool sev_es_support = (eax & (1<<3)) != 0; + bool sev_snp_support = (eax & (1<<4)) != 0; + + uint8_t cbitpos = ebx & 0x3f; + uint8_t reduced_phys_bits = (ebx >> 6) & 0x3f; + + FILE *file; + char filename[] = "/run/qemu-server/hw-params.json"; + + mkdir("/run/qemu-server/", 0755); + + file = fopen(filename, "w"); + if (file == NULL) { + perror("Error opening file"); + return 1; + } + + fprintf(file, + "{" + " \"amd-sev\": {" + " \"cbitpos\": %u," + " \"reduced-phys-bits\": %u," + " \"sev-support\": %s," + " \"sev-support-es\": %s," + " \"sev-support-snp\": %s" + " }" + " }\n", + cbitpos, + reduced_phys_bits, + sev_support ? "true" : "false", + sev_es_support ? "true" : "false", + sev_snp_support ? "true" : "false" + ); + + fclose(file); + return 0; +} diff --git a/query-machine-params/query-machine-params.service b/query-machine-params/query-machine-params.service new file mode 100644 index 0000000..774fc7f --- /dev/null +++ b/query-machine-params/query-machine-params.service @@ -0,0 +1,12 @@ +[Unit] +Description=read AMD SEV parameters +RequiresMountsFor=/run +Before=pve-ha-lrm.service +Before=pve-guests.service + +[Service] +ExecStart=/usr/libexec/qemu-server/query-machine-params +Type=oneshot + +[Install] +WantedBy=multi-user.target -- 2.39.2 _______________________________________________ pve-devel mailing list pve-devel@lists.proxmox.com https://lists.proxmox.com/cgi-bin/mailman/listinfo/pve-devel