diff options
| author | Sean Christopherson <seanjc@google.com> | 2023-08-15 10:42:15 -0700 |
|---|---|---|
| committer | Sean Christopherson <seanjc@google.com> | 2023-08-25 09:05:56 -0700 |
| commit | 9ca0c1a1265c03d54f1c71005ea0375f9bccabee (patch) | |
| tree | 7272a43c0dd3ce6e1425ee6eb327468a28969f1d /arch/x86/kvm | |
| parent | 7d18eef13622d84af93086ae79f081692516ba85 (diff) | |
KVM: VMX: Delete ancient pr_warn() about KVM_SET_TSS_ADDR not being set
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to try and help people running outdated qemu-kvm versions, the message got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@tarent.de>
Closes: https://lkml.kernel.org/r/f1afa6c0-cde2-ab8b-ea71-bfa62a45b956%40tarent.de
Link: https://lore.kernel.org/r/20230815174215.433222-1-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Diffstat (limited to 'arch/x86/kvm')
| -rw-r--r-- | arch/x86/kvm/vmx/vmx.c | 7 |
1 files changed, 0 insertions, 7 deletions
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index f848f43fa3e2..b0093b8a72d2 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -3047,13 +3047,6 @@ 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); |