Delete KVM's printk about KVM_SET_TSS_ADDR not being called. When the
printk was added by commit 776e58ea3d37 ("KVM: unbreak userspace that does
not sets tss address"), KVM also stuffed a "hopefully safe" value, i.e.
the message wasn't purely informational. For reasons unknown, ostensibly
to try and help people running outdated qemu-kvm versions, the message got
left behind when KVM's stuffing was removed by commit 4918c6ca6838
("KVM: VMX: Require KVM_SET_TSS_ADDR being called prior to running a VCPU").
Today, the message is completely nonsensical, as it has been over a decade
since KVM supported userspace running a Real Mode guest, on a CPU without
unrestricted guest support, without doing KVM_SET_TSS_ADDR before KVM_RUN.
I.e. KVM's ABI has required KVM_SET_TSS_ADDR for 10+ years.
To make matters worse, the message is prone to false positives as it
triggers when simply *creating* a vCPU due to RESET putting vCPUs into
Real Mode, even when the user has no intention of ever *running* the vCPU
in a Real Mode. E.g. KVM selftests stuff 64-bit mode and never touch Real
Mode, but trigger the message even though they run just fine without
doing KVM_SET_TSS_ADDR. Creating "dummy" vCPUs, e.g. to probe features,
can also trigger the message. In both scenarios, the message confuses
users and falsely implies that they've done something wrong.
Reported-by: Thorsten Glaser <t.glaser@xxxxxxxxx>
Closes: https://lkml.kernel.org/r/f1afa6c0-cde2-ab8b-ea71-bfa62a45b956%40tarent.de
Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
---
arch/x86/kvm/vmx/vmx.c | 7 -------
1 file changed, 7 deletions(-)
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 8cf1c00d9352..aadbe1a23e3a 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -3061,13 +3061,6 @@ static void enter_rmode(struct kvm_vcpu *vcpu)
vmx->rmode.vm86_active = 1;
- /*
- * Very old userspace does not call KVM_SET_TSS_ADDR before entering
- * vcpu. Warn the user that an update is overdue.
- */
- if (!kvm_vmx->tss_addr)
- pr_warn_once("KVM_SET_TSS_ADDR needs to be called before running vCPU\n");
-
vmx_segment_cache_clear(vmx);
vmcs_writel(GUEST_TR_BASE, kvm_vmx->tss_addr);
base-commit: 240f736891887939571854bd6d734b6c9291f22e
--
2.41.0.694.ge786442a9b-goog
