From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0D598C4332F for ; Wed, 2 Nov 2022 02:51:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230480AbiKBCvG (ORCPT ); Tue, 1 Nov 2022 22:51:06 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40482 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230474AbiKBCvF (ORCPT ); Tue, 1 Nov 2022 22:51:05 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BD26F21E05 for ; Tue, 1 Nov 2022 19:51:03 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 67CFFB82077 for ; Wed, 2 Nov 2022 02:51:02 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4054DC433D6; Wed, 2 Nov 2022 02:50:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1667357461; bh=N4ahiQRFXxVftQoDrX2puPRcqc1lykzJo2dePMMxvv8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=N25XM4GOEHgywuzD2xUBc+RVTXl4+/zgOa/blx/4FDgmPb5gn9vdWpZFwnFtrKSZD WLzHY7tL/19mTomoRxqaNAqp3uCXh9HODwo5wOkPG+UdSBLGWHr/Ag/RnEL1gU1x3/ 96xLMqNqyhYUkyYPYiHYafv6DcfjnuewBdjojczo= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Anup Patel , Atish Patra , Anup Patel , Sasha Levin Subject: [PATCH 6.0 173/240] RISC-V: KVM: Fix kvm_riscv_vcpu_timer_pending() for Sstc Date: Wed, 2 Nov 2022 03:32:28 +0100 Message-Id: <20221102022115.298920791@linuxfoundation.org> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20221102022111.398283374@linuxfoundation.org> References: <20221102022111.398283374@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Anup Patel [ Upstream commit cea8896bd936135559253e9b23340cfa1cdf0caf ] The kvm_riscv_vcpu_timer_pending() checks per-VCPU next_cycles and per-VCPU software injected VS timer interrupt. This function returns incorrect value when Sstc is available because the per-VCPU next_cycles are only updated by kvm_riscv_vcpu_timer_save() called from kvm_arch_vcpu_put(). As a result, when Sstc is available the VCPU does not block properly upon WFI traps. To fix the above issue, we introduce kvm_riscv_vcpu_timer_sync() which will update per-VCPU next_cycles upon every VM exit instead of kvm_riscv_vcpu_timer_save(). Fixes: 8f5cb44b1bae ("RISC-V: KVM: Support sstc extension") Signed-off-by: Anup Patel Reviewed-by: Atish Patra Signed-off-by: Anup Patel Signed-off-by: Sasha Levin --- arch/riscv/include/asm/kvm_vcpu_timer.h | 1 + arch/riscv/kvm/vcpu.c | 3 +++ arch/riscv/kvm/vcpu_timer.c | 17 +++++++++++++++-- 3 files changed, 19 insertions(+), 2 deletions(-) diff --git a/arch/riscv/include/asm/kvm_vcpu_timer.h b/arch/riscv/include/asm/kvm_vcpu_timer.h index 0d8fdb8ec63a..82f7260301da 100644 --- a/arch/riscv/include/asm/kvm_vcpu_timer.h +++ b/arch/riscv/include/asm/kvm_vcpu_timer.h @@ -45,6 +45,7 @@ int kvm_riscv_vcpu_timer_deinit(struct kvm_vcpu *vcpu); int kvm_riscv_vcpu_timer_reset(struct kvm_vcpu *vcpu); void kvm_riscv_vcpu_timer_restore(struct kvm_vcpu *vcpu); void kvm_riscv_guest_timer_init(struct kvm *kvm); +void kvm_riscv_vcpu_timer_sync(struct kvm_vcpu *vcpu); void kvm_riscv_vcpu_timer_save(struct kvm_vcpu *vcpu); bool kvm_riscv_vcpu_timer_pending(struct kvm_vcpu *vcpu); diff --git a/arch/riscv/kvm/vcpu.c b/arch/riscv/kvm/vcpu.c index 2ef33d5d94d1..f692c0716aa7 100644 --- a/arch/riscv/kvm/vcpu.c +++ b/arch/riscv/kvm/vcpu.c @@ -698,6 +698,9 @@ void kvm_riscv_vcpu_sync_interrupts(struct kvm_vcpu *vcpu) clear_bit(IRQ_VS_SOFT, &v->irqs_pending); } } + + /* Sync-up timer CSRs */ + kvm_riscv_vcpu_timer_sync(vcpu); } int kvm_riscv_vcpu_set_interrupt(struct kvm_vcpu *vcpu, unsigned int irq) diff --git a/arch/riscv/kvm/vcpu_timer.c b/arch/riscv/kvm/vcpu_timer.c index 185f2386a747..ad34519c8a13 100644 --- a/arch/riscv/kvm/vcpu_timer.c +++ b/arch/riscv/kvm/vcpu_timer.c @@ -320,20 +320,33 @@ void kvm_riscv_vcpu_timer_restore(struct kvm_vcpu *vcpu) kvm_riscv_vcpu_timer_unblocking(vcpu); } -void kvm_riscv_vcpu_timer_save(struct kvm_vcpu *vcpu) +void kvm_riscv_vcpu_timer_sync(struct kvm_vcpu *vcpu) { struct kvm_vcpu_timer *t = &vcpu->arch.timer; if (!t->sstc_enabled) return; - t = &vcpu->arch.timer; #if defined(CONFIG_32BIT) t->next_cycles = csr_read(CSR_VSTIMECMP); t->next_cycles |= (u64)csr_read(CSR_VSTIMECMPH) << 32; #else t->next_cycles = csr_read(CSR_VSTIMECMP); #endif +} + +void kvm_riscv_vcpu_timer_save(struct kvm_vcpu *vcpu) +{ + struct kvm_vcpu_timer *t = &vcpu->arch.timer; + + if (!t->sstc_enabled) + return; + + /* + * The vstimecmp CSRs are saved by kvm_riscv_vcpu_timer_sync() + * upon every VM exit so no need to save here. + */ + /* timer should be enabled for the remaining operations */ if (unlikely(!t->init_done)) return; -- 2.35.1