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 B8C64BA44 for ; Tue, 7 Mar 2023 17:50:33 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 20526C433D2; Tue, 7 Mar 2023 17:50:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1678211433; bh=ne7neqkItqvg0XeQ3WwHfJQN1eY4Yiq+9c39Y0Y3f6U=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=M5IPoYmXwC8xD6ZR9PVKn69NWQBLwh28tIwyE24oYtJ2w4YjIeRyZ1dMXAQMUlFAE cKs/9Tq7ra0A7zFJkyDW8dkVmiKpL/6zt2sHZmsaJRcnI2TbbGKAJFCRYwvjhqUnz1 S7fk9OLqXGMZrrFSKBwVvAvGx86cW8+Icc2aHLbA= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Paolo Bonzini , Maxim Levitsky , Sean Christopherson Subject: [PATCH 6.2 0829/1001] KVM: SVM: Process ICR on AVIC IPI delivery failure due to invalid target Date: Tue, 7 Mar 2023 18:00:01 +0100 Message-Id: <20230307170057.750110209@linuxfoundation.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230307170022.094103862@linuxfoundation.org> References: <20230307170022.094103862@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Sean Christopherson commit 5aede752a839904059c2b5d68be0dc4501c6c15f upstream. Emulate ICR writes on AVIC IPI failures due to invalid targets using the same logic as failures due to invalid types. AVIC acceleration fails if _any_ of the targets are invalid, and crucially VM-Exits before sending IPIs to targets that _are_ valid. In logical mode, the destination is a bitmap, i.e. a single IPI can target multiple logical IDs. Doing nothing causes KVM to drop IPIs if at least one target is valid and at least one target is invalid. Fixes: 18f40c53e10f ("svm: Add VMEXIT handlers for AVIC") Cc: stable@vger.kernel.org Reviewed-by: Paolo Bonzini Reviewed-by: Maxim Levitsky Signed-off-by: Sean Christopherson Message-Id: <20230106011306.85230-5-seanjc@google.com> Signed-off-by: Paolo Bonzini Signed-off-by: Greg Kroah-Hartman --- arch/x86/kvm/svm/avic.c | 16 +++++++++------- 1 file changed, 9 insertions(+), 7 deletions(-) --- a/arch/x86/kvm/svm/avic.c +++ b/arch/x86/kvm/svm/avic.c @@ -502,14 +502,18 @@ int avic_incomplete_ipi_interception(str trace_kvm_avic_incomplete_ipi(vcpu->vcpu_id, icrh, icrl, id, index); switch (id) { + case AVIC_IPI_FAILURE_INVALID_TARGET: case AVIC_IPI_FAILURE_INVALID_INT_TYPE: /* * Emulate IPIs that are not handled by AVIC hardware, which - * only virtualizes Fixed, Edge-Triggered INTRs. The exit is - * a trap, e.g. ICR holds the correct value and RIP has been - * advanced, KVM is responsible only for emulating the IPI. - * Sadly, hardware may sometimes leave the BUSY flag set, in - * which case KVM needs to emulate the ICR write as well in + * only virtualizes Fixed, Edge-Triggered INTRs, and falls over + * if _any_ targets are invalid, e.g. if the logical mode mask + * is a superset of running vCPUs. + * + * The exit is a trap, e.g. ICR holds the correct value and RIP + * has been advanced, KVM is responsible only for emulating the + * IPI. Sadly, hardware may sometimes leave the BUSY flag set, + * in which case KVM needs to emulate the ICR write as well in * order to clear the BUSY flag. */ if (icrl & APIC_ICR_BUSY) @@ -525,8 +529,6 @@ int avic_incomplete_ipi_interception(str */ avic_kick_target_vcpus(vcpu->kvm, apic, icrl, icrh, index); break; - case AVIC_IPI_FAILURE_INVALID_TARGET: - break; case AVIC_IPI_FAILURE_INVALID_BACKING_PAGE: WARN_ONCE(1, "Invalid backing page\n"); break;