# \[PATCH 5.12 150/161\] KVM: SVM: Truncate GPR value for DR and CR accesses in !64-bit mode - From: Greg Kroah-Hartman \ - Date: 2021-06-08 19:32:17 - List: stable - Page: https://ratatoskr.run/stable/2021/06/1407508 - Thread: https://ratatoskr.run/stable/2021/06/1407342/t/2.md ```text From: Sean Christopherson commit 0884335a2e653b8a045083aa1d57ce74269ac81d upstream. Drop bits 63:32 on loads/stores to/from DRs and CRs when the vCPU is not in 64-bit mode. The APM states bits 63:32 are dropped for both DRs and CRs: In 64-bit mode, the operand size is fixed at 64 bits without the need for a REX prefix. In non-64-bit mode, the operand size is fixed at 32 bits and the upper 32 bits of the destination are forced to 0. Fixes: 7ff76d58a9dc ("KVM: SVM: enhance MOV CR intercept handler") Fixes: cae3797a4639 ("KVM: SVM: enhance mov DR intercept handler") Cc: Signed-off-by: Sean Christopherson Message-Id: [ref] Signed-off-by: Paolo Bonzini Signed-off-by: Sudip Mukherjee Signed-off-by: Greg Kroah-Hartman --- arch/x86/kvm/svm/svm.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -2532,7 +2532,7 @@ static int cr_interception(struct vcpu_s err = 0; if (cr >= 16) { /* mov to cr */ cr -= 16; - val = kvm_register_read(&svm->vcpu, reg); + val = kvm_register_readl(&svm->vcpu, reg); trace_kvm_cr_write(cr, val); switch (cr) { case 0: @@ -2578,7 +2578,7 @@ static int cr_interception(struct vcpu_s kvm_queue_exception(&svm->vcpu, UD_VECTOR); return 1; } - kvm_register_write(&svm->vcpu, reg, val); + kvm_register_writel(&svm->vcpu, reg, val); trace_kvm_cr_read(cr, val); } return kvm_complete_insn_gp(&svm->vcpu, err); @@ -2643,11 +2643,11 @@ static int dr_interception(struct vcpu_s dr = svm->vmcb->control.exit_code - SVM_EXIT_READ_DR0; if (dr >= 16) { /* mov to DRn */ dr -= 16; - val = kvm_register_read(&svm->vcpu, reg); + val = kvm_register_readl(&svm->vcpu, reg); err = kvm_set_dr(&svm->vcpu, dr, val); } else { kvm_get_dr(&svm->vcpu, dr, &val); - kvm_register_write(&svm->vcpu, reg, val); + kvm_register_writel(&svm->vcpu, reg, val); } return kvm_complete_insn_gp(&svm->vcpu, err); ```