From 498df2a7470e09d6cb0204f45eeb30d7ae796465 Mon Sep 17 00:00:00 2001 From: Lara Lazier Date: Wed, 16 Jun 2021 14:39:06 +0200 Subject: target/i386: Added consistency checks for CR0 The combination of unset CD and set NW bit in CR0 is illegal. CR0[63:32] are also reserved and need to be zero. (AMD64 Architecture Programmer's Manual, V2, 15.5) Signed-off-by: Lara Lazier Message-Id: <20210616123907.17765-4-laramglazier@gmail.com> Signed-off-by: Paolo Bonzini --- target/i386/cpu.h | 2 ++ target/i386/svm.h | 2 ++ target/i386/tcg/sysemu/svm_helper.c | 12 +++++++++--- 3 files changed, 13 insertions(+), 3 deletions(-) (limited to 'target') diff --git a/target/i386/cpu.h b/target/i386/cpu.h index 64b4e46..1e11071 100644 --- a/target/i386/cpu.h +++ b/target/i386/cpu.h @@ -224,6 +224,8 @@ typedef enum X86Seg { #define CR0_NE_MASK (1U << 5) #define CR0_WP_MASK (1U << 16) #define CR0_AM_MASK (1U << 18) +#define CR0_NW_MASK (1U << 29) +#define CR0_CD_MASK (1U << 30) #define CR0_PG_MASK (1U << 31) #define CR4_VME_MASK (1U << 0) diff --git a/target/i386/svm.h b/target/i386/svm.h index 87965e5..5098733 100644 --- a/target/i386/svm.h +++ b/target/i386/svm.h @@ -135,6 +135,8 @@ #define SVM_NPTEXIT_GPA (1ULL << 32) #define SVM_NPTEXIT_GPT (1ULL << 33) +#define SVM_CR0_RESERVED_MASK 0xffffffff00000000U + struct QEMU_PACKED vmcb_control_area { uint16_t intercept_cr_read; uint16_t intercept_cr_write; diff --git a/target/i386/tcg/sysemu/svm_helper.c b/target/i386/tcg/sysemu/svm_helper.c index 902bf03..1c2dbc1 100644 --- a/target/i386/tcg/sysemu/svm_helper.c +++ b/target/i386/tcg/sysemu/svm_helper.c @@ -73,6 +73,7 @@ void helper_vmrun(CPUX86State *env, int aflag, int next_eip_addend) uint32_t event_inj; uint32_t int_ctl; uint32_t asid; + uint64_t new_cr0; cpu_svm_check_intercept_param(env, SVM_EXIT_VMRUN, 0, GETPC()); @@ -192,13 +193,18 @@ void helper_vmrun(CPUX86State *env, int aflag, int next_eip_addend) env->idt.limit = x86_ldl_phys(cs, env->vm_vmcb + offsetof(struct vmcb, save.idtr.limit)); + new_cr0 = x86_ldq_phys(cs, env->vm_vmcb + offsetof(struct vmcb, save.cr0)); + if (new_cr0 & SVM_CR0_RESERVED_MASK) { + cpu_vmexit(env, SVM_EXIT_ERR, 0, GETPC()); + } + if ((new_cr0 & CR0_NW_MASK) && !(new_cr0 & CR0_CD_MASK)) { + cpu_vmexit(env, SVM_EXIT_ERR, 0, GETPC()); + } /* clear exit_info_2 so we behave like the real hardware */ x86_stq_phys(cs, env->vm_vmcb + offsetof(struct vmcb, control.exit_info_2), 0); - cpu_x86_update_cr0(env, x86_ldq_phys(cs, - env->vm_vmcb + offsetof(struct vmcb, - save.cr0))); + cpu_x86_update_cr0(env, new_cr0); cpu_x86_update_cr4(env, x86_ldq_phys(cs, env->vm_vmcb + offsetof(struct vmcb, save.cr4))); -- cgit v1.1