From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-208.mta0.migadu.com (out-208.mta0.migadu.com [91.218.175.208]) (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 5A9382AB3B for ; Fri, 6 Oct 2023 18:11:36 +0000 (UTC) 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="ekM8vZzY" Date: Fri, 6 Oct 2023 18:11:30 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1696615894; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=L8lSHiz12Aav9oLTb3CvxyN/1lWwyX+P2/Gb3/jsWN8=; b=ekM8vZzYxNkS7ov34yAiI2ikVogB11+UMM8enyKgtFmPU0bJJuCG03J+tEnrvdgqESM/9n sQbJ/RtmtDy5DsVN276UDVnQt8i7GrUkAE2HwzwTB0DeQVs0XaUQ/Kgva1YqOcqt9cqGfQ 240/dslRH4LQvWMLIdJzmBarVpzPiWI= X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Oliver Upton To: Marc Zyngier Cc: kvmarm@lists.linux.dev, kvm@vger.kernel.org, James Morse , Suzuki K Poulose , Zenghui Yu Subject: Re: [PATCH 0/3] KVM: arm64: Load the stage-2 MMU from vcpu_load() for VHE Message-ID: References: <20231006093600.1250986-1-oliver.upton@linux.dev> <8634yongw3.wl-maz@kernel.org> <861qe8nd45.wl-maz@kernel.org> <86zg0vnaen.wl-maz@kernel.org> <86y1gfn67v.wl-maz@kernel.org> Precedence: bulk X-Mailing-List: kvmarm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <86y1gfn67v.wl-maz@kernel.org> X-Migadu-Flow: FLOW_OUT Hey Marc, On Fri, Oct 06, 2023 at 04:03:32PM +0100, Marc Zyngier wrote: > On Fri, 06 Oct 2023 14:33:04 +0100, > Marc Zyngier wrote: > > Still talking to myself! :D Seems like you had a good bit of fun :) > > > > However, this isn't enough. > > > > [ 63.450113] Oh crap 400000435c001 vs 3000004430001 > > > > So there are situations where we end-up with the wrong VTTBR, rather > > than the wrong VMID, which is even worse. Haven't worked out the > > scenario yet, but it apparently involves being preempted by a vcpu > > from a different VM and not doing the right thing. > > Actually, no. It is the MMU notifiers kicking in and performing TLB > invalidation for a guest while we're in the context of another. The > joy of running 4 large VMs on a box with 2GB of RAM, basically running > from swap. Whelp, looks like my self-rule of no patches on the list after midnight is in force again. Clearly this was all quite gently tested, thanks for being the guinea pig. > There's the sum of my hacks, which keeps the box alive. Thanks! I'll roll it into v2 so we have something that actually works. -- Thanks, Oliver