From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 58D5A342523; Thu, 2 Jul 2026 16:32:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783009973; cv=none; b=mJgaBGqYbmJpCKq8pQL5rlpKzhfcGftZT2O0rldLqaqBSTIuyfNWhgpkM3Gq1X3l+7wphZcaBfBSON4kCjhb5/juTYSLO2/HZPEcundEyiByt/jhdVVmNav6MsJaXWFFJaZ+YAGPmpAUEFNF5eG7OhgD6Nr+nRMeyFvOoO8CcFY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783009973; c=relaxed/simple; bh=tEZuOmFc4PYo6NJp6MItgctjIgr3W73mEVvlZ1F1LhQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=ENYrBQYZdI7cEeR7dyGr5BGrF/i/5HIbGHxXo5plxf0Zle/POI5U4GUFMKCtkq7WCNtNHQ0BqwHD81N1gdvWNNkIBAy0NrBGf0QsTvTr1sexERCa75Mhpq/iOMBtZ6ZbwCy9TXAsOpGLo3SeBA4KaCV3JXiHy14Ow6TQQEC2swY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=Xpv0fPJX; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="Xpv0fPJX" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B71421F000E9; Thu, 2 Jul 2026 16:32:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1783009972; bh=sccGH+bM2jgJjbatt6ptB71ayzEeib2JYY6H7Bvk8KY=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=Xpv0fPJXyytTJ67wvi4gr1GCb2PEhXBNJQwwWPTYeoCoqYHZTfYwX71mttUH8vZEV XAr1XZAqBdaEyQNBme1+lsfiLiJBE6VsGl2jOCmKU1jYpeRoUp7uRZPJlPWV71sGO0 XMBRqG1TYqGmLvnq4y5hkfwqKJu3UdmsbxIBkZw8= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Sean Christopherson , Nicholas Dudar , Sasha Levin Subject: [PATCH 6.1 018/129] KVM: nVMX: Add a helper to get highest pending from Posted Interrupt vector Date: Thu, 2 Jul 2026 18:18:57 +0200 Message-ID: <20260702155112.539597314@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260702155112.163984240@linuxfoundation.org> References: <20260702155112.163984240@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: Sean Christopherson commit d83c36d822be44db4bad0c43bea99c8908f54117 upstream. Add a helper to retrieve the highest pending vector given a Posted Interrupt descriptor. While the actual operation is straightforward, it's surprisingly easy to mess up, e.g. if one tries to reuse lapic.c's find_highest_vector(), which doesn't work with PID.PIR due to the APIC's IRR and ISR component registers being physically discontiguous (they're 4-byte registers aligned at 16-byte intervals). To make PIR handling more consistent with respect to IRR and ISR handling, return -1 to indicate "no interrupt pending". Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20240607172609.3205077-2-seanjc@google.com Signed-off-by: Sean Christopherson [ Nicholas Dudar: backport to 6.1.y. 6.1.y defines struct pi_desc in posted_intr.h and predates the move to , so the helper and the include go in posted_intr.h. ] Signed-off-by: Nicholas Dudar Signed-off-by: Sasha Levin --- arch/x86/kvm/vmx/nested.c | 5 +++-- arch/x86/kvm/vmx/posted_intr.h | 10 ++++++++++ 2 files changed, 13 insertions(+), 2 deletions(-) diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c index bdc462944cb082..7d8e18dbe8531b 100644 --- a/arch/x86/kvm/vmx/nested.c +++ b/arch/x86/kvm/vmx/nested.c @@ -12,6 +12,7 @@ #include "mmu.h" #include "nested.h" #include "pmu.h" +#include "posted_intr.h" #include "sgx.h" #include "trace.h" #include "vmx.h" @@ -3818,8 +3819,8 @@ static int vmx_complete_nested_posted_interrupt(struct kvm_vcpu *vcpu) if (!pi_test_and_clear_on(vmx->nested.pi_desc)) return 0; - max_irr = find_last_bit((unsigned long *)vmx->nested.pi_desc->pir, 256); - if (max_irr != 256) { + max_irr = pi_find_highest_vector(vmx->nested.pi_desc); + if (max_irr > 0) { vapic_page = vmx->nested.virtual_apic_map.hva; if (!vapic_page) goto mmio_needed; diff --git a/arch/x86/kvm/vmx/posted_intr.h b/arch/x86/kvm/vmx/posted_intr.h index 26992076552ef1..88cea0dac7204b 100644 --- a/arch/x86/kvm/vmx/posted_intr.h +++ b/arch/x86/kvm/vmx/posted_intr.h @@ -2,6 +2,8 @@ #ifndef __KVM_X86_VMX_POSTED_INTR_H #define __KVM_X86_VMX_POSTED_INTR_H +#include + #define POSTED_INTR_ON 0 #define POSTED_INTR_SN 1 @@ -103,4 +105,12 @@ int vmx_pi_update_irte(struct kvm *kvm, unsigned int host_irq, uint32_t guest_irq, bool set); void vmx_pi_start_assignment(struct kvm *kvm); +static inline int pi_find_highest_vector(struct pi_desc *pi_desc) +{ + int vec; + + vec = find_last_bit((unsigned long *)pi_desc->pir, 256); + return vec < 256 ? vec : -1; +} + #endif /* __KVM_X86_VMX_POSTED_INTR_H */ -- 2.53.0