From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-186.mta0.migadu.com (out-186.mta0.migadu.com [91.218.175.186]) (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 3B39D1DE896 for ; Fri, 8 Nov 2024 22:24:55 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.186 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1731104696; cv=none; b=JIL8LWhxrlA7j/RvP+DrIy+7WascA0ZvwYXsDtcrdZxs+7HLSLdGS3lQqVK85Z4x2WuI4jGQdVb6ltH+TbBJzzRhRVJBZW3Uabsjx3KNPoNSM/FzWbcY+LwRCrWG7gu0DBk8KNH+8CjizPhAASQ22YzKrQv08030QNA78ZdKLx4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1731104696; c=relaxed/simple; bh=pzMEgZ0cCKxbR8Ki7kJGZSbn2mPflnDXtuupE4LeE2M=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=JB9IIQ9AwHX4qnBhYicWIaC3LNWI0b4zhPx39jPAHBhnUslcVbZAWAl+ONsieGXE8Ff0mULzwbkdF/La96MdHrnmKGe9N8CGOBSm+juGrRQ/BRWp/pSEhJdtFSN2OQ5orKkvLPPiJxfoqyC1pPyr2ZtQviNQxOO60A+YCyx5rFY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=XgSu9NXd; arc=none smtp.client-ip=91.218.175.186 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="XgSu9NXd" X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1731104693; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=xPj8Cqstn6hlWS1zlDDmAUdgx8D+IUrp/0Ts6Bscyrk=; b=XgSu9NXd76opuN1Z3ZH6NLzLgnZJRTdIvpa7mk13H5ml8RsVg1qYeJ2KlJNBLMVIpNB3EQ WBaUTYwkS+fb6pwi5o74Uh85tnlvRKGUfpXVx8ygun7F5nVv1Bs1op1c4Z6GSQ7CVpTj/X OlDEyEke6QVvw5Hg+iltngj894H4Spw= From: Oliver Upton To: kvmarm@lists.linux.dev Cc: Marc Zyngier , Joey Gouly , Suzuki K Poulose , Zenghui Yu , Mingwei Zhang , Colton Lewis , Alexandru Elisei , Oliver Upton Subject: [PATCH 05/15] KVM: arm64: Evaluate debug owner at vcpu_load() Date: Fri, 8 Nov 2024 14:24:09 -0800 Message-Id: <20241108222418.1677420-6-oliver.upton@linux.dev> In-Reply-To: <20241108222418.1677420-1-oliver.upton@linux.dev> References: <20241108222418.1677420-1-oliver.upton@linux.dev> Precedence: bulk X-Mailing-List: kvmarm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT In preparation for tossing the debug_ptr mess, introduce an enumeration to track the ownership of the debug registers while in the guest. Update the owner at vcpu_load() based on whether the host needs to steal the guest's debug context or if breakpoints/watchpoints are actively in use. Signed-off-by: Oliver Upton --- arch/arm64/include/asm/kvm_host.h | 10 ++++++++++ arch/arm64/kvm/arm.c | 1 + arch/arm64/kvm/debug.c | 23 +++++++++++++++++++++++ 3 files changed, 34 insertions(+) diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index cf5cdc468aa4..f954b082dc4f 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -756,6 +756,12 @@ struct kvm_vcpu_arch { struct kvm_guest_debug_arch vcpu_debug_state; struct kvm_guest_debug_arch external_debug_state; + enum { + VCPU_DEBUG_FREE, + VCPU_DEBUG_HOST_OWNED, + VCPU_DEBUG_GUEST_OWNED, + } debug_owner; + /* VGIC state */ struct vgic_cpu vgic_cpu; struct arch_timer_cpu timer_cpu; @@ -1345,10 +1351,14 @@ void kvm_arm_vcpu_init_debug(struct kvm_vcpu *vcpu); void kvm_arm_setup_debug(struct kvm_vcpu *vcpu); void kvm_arm_clear_debug(struct kvm_vcpu *vcpu); void kvm_arm_reset_debug_ptr(struct kvm_vcpu *vcpu); +void kvm_vcpu_load_debug(struct kvm_vcpu *vcpu); #define kvm_vcpu_os_lock_enabled(vcpu) \ (!!(__vcpu_sys_reg(vcpu, OSLSR_EL1) & OSLSR_EL1_OSLK)) +#define kvm_host_owns_debug_regs(vcpu) \ + ((vcpu)->arch.debug_owner == VCPU_DEBUG_HOST_OWNED) + int kvm_arm_vcpu_arch_set_attr(struct kvm_vcpu *vcpu, struct kvm_device_attr *attr); int kvm_arm_vcpu_arch_get_attr(struct kvm_vcpu *vcpu, diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c index 3822774840e1..a068337da52a 100644 --- a/arch/arm64/kvm/arm.c +++ b/arch/arm64/kvm/arm.c @@ -598,6 +598,7 @@ void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu) kvm_vgic_load(vcpu); kvm_timer_vcpu_load(vcpu); + kvm_vcpu_load_debug(vcpu); if (has_vhe()) kvm_vcpu_load_vhe(vcpu); kvm_arch_vcpu_load_fp(vcpu); diff --git a/arch/arm64/kvm/debug.c b/arch/arm64/kvm/debug.c index 97d0c6fd5f61..e2798a4eec47 100644 --- a/arch/arm64/kvm/debug.c +++ b/arch/arm64/kvm/debug.c @@ -313,3 +313,26 @@ void kvm_init_host_debug_data(void) !(read_sysreg_s(SYS_TRBIDR_EL1) & TRBIDR_EL1_P)) host_data_set_flag(HAS_TRBE); } + +void kvm_vcpu_load_debug(struct kvm_vcpu *vcpu) +{ + u64 mdscr; + + /* Must be called before kvm_vcpu_load_vhe() */ + KVM_BUG_ON(vcpu_get_flag(vcpu, SYSREGS_ON_CPU), vcpu->kvm); + + if (vcpu->guest_debug || kvm_vcpu_os_lock_enabled(vcpu)) { + vcpu->arch.debug_owner = VCPU_DEBUG_HOST_OWNED; + } else { + mdscr = vcpu_read_sys_reg(vcpu, MDSCR_EL1); + + /* + * Eagerly restore the debug state if the debugger is actively + * in use + */ + if (mdscr & (MDSCR_EL1_KDE | MDSCR_EL1_MDE)) + vcpu->arch.debug_owner = VCPU_DEBUG_GUEST_OWNED; + else + vcpu->arch.debug_owner = VCPU_DEBUG_FREE; + } +} -- 2.39.5