From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 7883A39CCF2 for ; Thu, 13 Aug 2026 17:51:50 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786643510; cv=none; b=abXd0wdRbPmw8V10pH19D6TrHtygAF0aB18HLq1H0I34I2S5UOpA5RhzqStJOg8ANKHUI6HDTjItahn7XgZ5OWMQx+Jx/e2yNGYD7Sj5RGDYilp4VczB59xBF+ztPLD0BRHzMRtG1cigdpPwH7iIoTkDQR3WES9mn2MzioBQbr0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786643510; c=relaxed/simple; bh=1W4IMzCRaYqXbF37BhC2gvXlfKI+e1Q7RdhojDSCfMg=; h=From:To:Subject:Date:Message-ID:In-Reply-To:References: Content-Type:MIME-Version; b=d7XLqipsUCgvQ84RdWn2Ac9KPhEviXf1Xw2Ek79VKg4tcVrB/FlgUN2YAECoJwjO2ghNi6bi8cjEc+dqxu73Me/ClMt4EZHaOU7jfaZ9RmvrwGW1iACfQkN7Z0kywSCJVdPATc29LbUK3nfCV1Oz+XaokVI7e9fOKrElk57z6Ew= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=aXP3f3qe; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="aXP3f3qe" Received: by smtp.kernel.org (Postfix) with ESMTPS id E9DBCC2BCF7 for ; Thu, 13 Aug 2026 17:51:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1786643509; bh=1W4IMzCRaYqXbF37BhC2gvXlfKI+e1Q7RdhojDSCfMg=; h=From:To:Subject:Date:In-Reply-To:References:From; b=aXP3f3qeNgV6cTJ8oHL0jK7XB5Q9LhlujC8JLbJg5XKvScmadx5B8ldZPdKvh2N50 T/WEBBdLmN+pGkGXogwi70Mxyn+56ucafKBxws7TSuDVSZXzWxRIu1JCDoNZeduoOP k/e9FeJOLtOi1eQQJiWwx7b/QiE2m09lJHl3g1ohrPB5895bjGBQjJ+xQyQSeD01DG x7qzU+R4JdQ1Hi4WR/P6uNBt5Ts/dSQv4m06Xi2/zhrzXkeW+ehDFtrxMEXMd4kG61 DUL5vVKBN7veCncFsRMYHClG8YT9kyvq5GLkmLiIIoKFKoUz2mQlUB+fZ4h/pJ8YZK E0zGUWTmBAJWg== Received: by aws-us-west-2-korg-bugzilla-1.web.codeaurora.org (Postfix, from userid 48) id D1B3DC53BC5; Thu, 13 Aug 2026 17:51:49 +0000 (UTC) From: bugzilla-daemon@kernel.org To: kvm@vger.kernel.org Subject: [Bug 221841] KVM: nested VMX eVMCS VMPTRLD/VMPTRST causes infinite VM-Exit loop due to missing RIP advance Date: Thu, 13 Aug 2026 17:51:49 +0000 X-Bugzilla-Reason: None X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: AssignedTo virtualization_kvm@kernel-bugs.osdl.org X-Bugzilla-Product: Virtualization X-Bugzilla-Component: kvm X-Bugzilla-Version: unspecified X-Bugzilla-Keywords: X-Bugzilla-Severity: high X-Bugzilla-Who: vkuznets@redhat.com X-Bugzilla-Status: NEW X-Bugzilla-Resolution: X-Bugzilla-Priority: P3 X-Bugzilla-Assigned-To: virtualization_kvm@kernel-bugs.osdl.org X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: Message-ID: In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Bugzilla-URL: https://bugzilla.kernel.org/ Auto-Submitted: auto-generated Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 https://bugzilla.kernel.org/show_bug.cgi?id=3D221841 --- Comment #4 from vkuznets@redhat.com --- (In reply to vkuznets from comment #2) > Ideally, we can try and see what genuine Hyper-V gives us > in this situation (by e.g. running an instrumented version of KVM there).= It > does not seem that we have an extreme urgency here so I can put it to my > backlog and try to get to it some time next week -- unless someone beats = me > to it of course! Tested on Azure. Apparently, VMPTRLD is completely unsupported and generates #UD right away, no matter if I give it the same 'enlightened' address or something else. VMPTRST, however, is different: before VMLAUNCH it gives us 0xffffffffffffffff even after we set a valid eVMCS pointer to the VP assist page. This is (AFAIU) somewhat similar to the architectural behavior when we execute VMPTRST with no current-VMCS pointer. After VMLAUNCH it works norma= lly and gives us the eVMCS pointer we used. I think it makes sense to mimic the behavior in KVM. --=20 You may reply to this email to add a comment. You are receiving this mail because: You are watching the assignee of the bug.=