From b7e8674a1d3d577a3e88e95d2dab6aac626eca41 Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Fri, 18 Jul 2025 18:03:48 +0200 Subject: [PATCH 083/115] i386/tdx: Validate phys_bits against host value MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit RH-Author: Paolo Bonzini RH-MergeRequest: 391: TDX support, including attestation and device assignment RH-Jira: RHEL-15710 RHEL-20798 RHEL-49728 RH-Acked-by: Yash Mankad RH-Acked-by: Peter Xu RH-Acked-by: David Hildenbrand RH-Commit: [83/115] 42a17d80e8c176a2dc4e2d3da0ea74f7fdb85577 (bonzini/rhel-qemu-kvm) For TDX guest, the phys_bits is not configurable and can only be host/native value. Validate phys_bits inside tdx_check_features(). Signed-off-by: Xiaoyao Li Reviewed-by: Daniel P. Berrangé Reviewed-by: Zhao Liu Link: https://lore.kernel.org/r/20250508150002.689633-55-xiaoyao.li@intel.com Signed-off-by: Paolo Bonzini (cherry picked from commit 907ee7b67e50a7eea2768c66e3ad67c9aa4ffd3c) Signed-off-by: Paolo Bonzini --- target/i386/host-cpu.c | 2 +- target/i386/host-cpu.h | 1 + target/i386/kvm/tdx.c | 8 ++++++++ 3 files changed, 10 insertions(+), 1 deletion(-) diff --git a/target/i386/host-cpu.c b/target/i386/host-cpu.c index 4a77ecc1fc..4ab536ab80 100644 --- a/target/i386/host-cpu.c +++ b/target/i386/host-cpu.c @@ -15,7 +15,7 @@ #include "sysemu/sysemu.h" /* Note: Only safe for use on x86(-64) hosts */ -static uint32_t host_cpu_phys_bits(void) +uint32_t host_cpu_phys_bits(void) { uint32_t eax; uint32_t host_phys_bits; diff --git a/target/i386/host-cpu.h b/target/i386/host-cpu.h index 6a9bc918ba..b97ec01c9b 100644 --- a/target/i386/host-cpu.h +++ b/target/i386/host-cpu.h @@ -10,6 +10,7 @@ #ifndef HOST_CPU_H #define HOST_CPU_H +uint32_t host_cpu_phys_bits(void); void host_cpu_instance_init(X86CPU *cpu); void host_cpu_max_instance_init(X86CPU *cpu); bool host_cpu_realizefn(CPUState *cs, Error **errp); diff --git a/target/i386/kvm/tdx.c b/target/i386/kvm/tdx.c index 3ec31d4872..b9c3ba3725 100644 --- a/target/i386/kvm/tdx.c +++ b/target/i386/kvm/tdx.c @@ -25,6 +25,7 @@ #include "cpu.h" #include "cpu-internal.h" +#include "host-cpu.h" #include "hw/i386/e820_memory_layout.h" #include "hw/i386/tdvf.h" #include "hw/i386/x86.h" @@ -879,6 +880,13 @@ static int tdx_check_features(X86ConfidentialGuest *cg, CPUState *cs) return -EINVAL; } + if (cpu->phys_bits != host_cpu_phys_bits()) { + error_report("TDX requires guest CPU physical bits (%u) " + "to match host CPU physical bits (%u)", + cpu->phys_bits, host_cpu_phys_bits()); + return -EINVAL; + } + return 0; } -- 2.50.1