As it stands now, we are hopeful we can swap out to WARP on Windows without any drop in coverage for software rendering (i.e. simultaneously with removing SwiftShader). Experimental support and testing for this will begin in Chrome 137.
On Thursday, April 10, 2025 at 12:47:33 PM UTC-4 Julie Powell wrote: > WebGL emulation is critical for many US entities that are running thin > client machines which don’t have access to a GPU. So far, the organizations > we’ve spoken to are on Windows so simultaneously putting an automatic > fallback to WARP in place once the fallback to SwiftShader is removed – > avoiding a period of time when a command line override would be required – > will allow them to continue operating. We have verified that the following > organizations are dependent on this capability (note that there are many > more outside of this list, both in the private and public sector): > Department of the Interior Bureau of Land Management, Office of Wildland > Fire, National Park Service, U.S. Geologic Survey, U.S. Fish and Wildlife > Service, Bureau of Indian Affairs, Air Force DCGS, Army Tactical Edge Node, > DCGS-Army, DCGS-USMC, USMC, USAF, USDA, NGA, DIA, Census, DHS, CISA, > FirstNet/NTIA (Commerce), NCIS, DTRA, STRATCOM, EUCOM, Idaho National > Guard, some universities, K-12 schools, National Geographic, and more. > > I am working with colleagues and international distributors to gauge the > usage of VMs running Linux which are doing web mapping and don’t have > access to GPU resources. I will come back with an update when I have one. > > On Monday, March 24, 2025 at 12:56:08 PM UTC-7 Matt George wrote: > >> Hi Rick, AFAIK it's only Windows, but currently reaching out to see if >> it's different for our distributors in Europe. >> >> Matt >> On Monday, March 24, 2025 at 10:38:19 AM UTC-7 Rick Byers wrote: >> >>> Thanks for chiming in Matt. Is the scenario you described Windows-only >>> (in which case we should be good with WARP), or also Linux? >>> >>> Rick >>> >>> On Mon, Mar 24, 2025 at 1:22 PM Matt George <matt...@gmail.com> wrote: >>> >>>> Very happy to hear about exploring the use of WARP on windows. >>>> >>>> Just wanted to chime in that from the Esri perspective, we also have a >>>> large number of users accessing our maps SDK from VMs without a GPU. This >>>> is done for security reasons, & not uncommon for public sector clients. We >>>> have a special codepath where when we detect software emulation is being >>>> used, we only render every X frames & then use css transforms in-between. >>>> This is fairly usable, though of course it's a much worse experience than >>>> having a GPU. >>>> >>> On Tuesday, March 11, 2025 at 1:11:42 AM UTC-7 Ashley Gullen wrote: >>>> >>>>> Thanks for the update David - that sounds like a much less disruptive >>>>> approach than removing it completely. >>>>> >>>>> >>>>> On Mon, 10 Mar 2025 at 19:26, David Adrian <dad...@google.com> wrote: >>>>> >>>>>> To cover the testing use case, we have provided a CLI flag to enable >>>>>> SwiftShader. This has been in the release notes since November. If this >>>>>> is >>>>>> insufficient, we could add an enterprise policy. >>>>>> >>>>>> However, rather than attempt a straight removal, we are going to take >>>>>> a multi-pronged approach to attempt to simultaneously reduce the >>>>>> situations >>>>>> where SwiftShader is available, while maintaining compatibility with >>>>>> devices that require it due to the GPU blocklist. >>>>>> >>>>>> - SwiftShader is already unused on many Mac clients, since it >>>>>> does not support ARM. We will run an experiment where we fully remove >>>>>> it on >>>>>> Mac, where usage is much smaller. We expect this will be ~fine. >>>>>> - Similarly, we will try the same on Linux, although this may not >>>>>> go as well, as there are not a large number of ARM Linux clients. >>>>>> - We will experiment with removing the automatic fallback to >>>>>> SwiftShader after 3 OOMs, limiting it to just the devices without a >>>>>> GPU or >>>>>> on the GPU blocklist. This should reduce the attack surface across >>>>>> the >>>>>> board, as attackers would be unable to arbitrarily cause SwiftShader >>>>>> to be >>>>>> used. In conjunction with this, we'll see if we can leverage Warp on >>>>>> Windows. >>>>>> >>>>>> If we can get to a state where SwiftShader is off by default on Mac >>>>>> and Linux, and replaced with Warp on Windows aside from the CLI flag, >>>>>> and >>>>>> the fallback is not triggerable by an attacker on systems with a >>>>>> "normal" >>>>>> GPU, we'll be in much better shape from a security standpoint. >>>>>> >>>>>> We will update this thread with the progress and results of these >>>>>> experiments as they roll out. >>>>>> >>>>>> >>>>>> On Mon, Mar 3, 2025 at 2:27 PM Rick Byers <rby...@chromium.org> >>>>>> wrote: >>>>>> >>>>>>> +1 that providing temporary enterprise policy exceptions is standard >>>>>>> practice <https://www.chromium.org/developers/enterprise-changes/> >>>>>>> for breaking changes that we predict may have enterprise impact. >>>>>>> >>>>>>> Rick >>>>>>> >>>>>>> On Mon, Mar 3, 2025 at 2:24 PM Erik Anderson < >>>>>>> erik.a...@microsoft.com> wrote: >>>>>>> >>>>>>>> Hi Geoff, >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> My suggestion re: a policy was not to have one that is supported >>>>>>>> indefinitely. >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> Many high-risk deprecations have had a policy lasting for, I >>>>>>>> believe, as little as 3 major version releases. Having such a thing >>>>>>>> helps >>>>>>>> mitigate the concern that the risk analysis was way off (which could >>>>>>>> then >>>>>>>> mean needing to do a stable respin if your risk analysis was off). If >>>>>>>> a >>>>>>>> policy is available, impacted enterprises can quickly self-remediate, >>>>>>>> report what broke once you flip over the default, and have a little >>>>>>>> bit >>>>>>>> more of a window to plan mitigations tied to the removal of the policy >>>>>>>> (since they’d now be aware of what broke and why). >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> Thanks, >>>>>>>> >>>>>>>> Erik >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> *From:* Ken Russell <k...@chromium.org> >>>>>>>> *Sent:* Monday, March 3, 2025 10:39 AM >>>>>>>> *To:* Ashley Gullen <ash...@scirra.com> >>>>>>>> *Cc:* Geoff Lang <geof...@google.com>; Erik Anderson < >>>>>>>> erik.a...@microsoft.com>; Rick Byers <rby...@chromium.org>; David >>>>>>>> Adrian <dad...@google.com>; blink-dev <blin...@chromium.org>; >>>>>>>> geof...@chromium.org <geof...@chromium.org> >>>>>>>> *Subject:* Re: [EXTERNAL] Re: [blink-dev] Intent to Remove: >>>>>>>> SwiftShader Fallback >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> It's feasible, but a significant amount of engineering work that >>>>>>>> our (Chrome Graphics) team would not be able to prioritize versus >>>>>>>> other >>>>>>>> current work that would impact a larger user base. >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> -Ken >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> On Fri, Feb 28, 2025 at 9:45 AM 'Ashley Gullen' via blink-dev < >>>>>>>> blin...@chromium.org> wrote: >>>>>>>> >>>>>>>> Is it feasible to have SwiftShader (or WARP) run in its own process >>>>>>>> with a stronger sandbox? >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> On Fri, 28 Feb 2025 at 15:25, Geoff Lang <geof...@google.com> >>>>>>>> wrote: >>>>>>>> >>>>>>>> Hey Erik, Ashley, Rick, >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> I want to be clear that I think having high WebGL availability is a >>>>>>>> good thing. I don't think that users with software WebGL have a great >>>>>>>> experience but it's likely better than no availability, at least for >>>>>>>> drawing static things. What pushes this over the line and warrants >>>>>>>> this >>>>>>>> discussion is that JITing code in the GPU process is a huge >>>>>>>> vulnerability >>>>>>>> and is a rapidly increasing attack target. >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> We're investigating WARP as an alternative on Windows. You are >>>>>>>> right that a large portion of the SwiftShader fallback is on machines >>>>>>>> with >>>>>>>> no GPUs (headless or VMs). There are just many unknowns about the >>>>>>>> quality >>>>>>>> and security of WARP, it will take a while to be confident in such a >>>>>>>> change >>>>>>>> and it still does not resolve the issue of JITing code in the weakly >>>>>>>> sandboxed GPU process. >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> Regarding corporate policy, I'd much rather have these users fall >>>>>>>> back in the same way as everyone else and work towards lowering the >>>>>>>> number >>>>>>>> of users in this position. It would mean supporting and testing a >>>>>>>> feature >>>>>>>> only used by enterprise users when we have no visibility into crashes, >>>>>>>> bugs >>>>>>>> or vulnerabilities that they face. >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> We're also disabling software fallback due to a crashes in the GPU >>>>>>>> driver (as opposed to blocklisted GPU). Right now any user can fairly >>>>>>>> easily trigger a GPU crash and fall back to software WebGL which opens >>>>>>>> up >>>>>>>> vulnerabilities to all users instead of the 2.7%. >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> Geoff >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> On Thu, Feb 27, 2025 at 3:28 PM Erik Anderson < >>>>>>>> erik.a...@microsoft.com> wrote: >>>>>>>> >>>>>>>> Hi David, >>>>>>>> >>>>>>>> The initial message states that SwiftShader primarily covers older >>>>>>>> Windows devices. Beyond those, there are a non-trivial set of >>>>>>>> enterprise >>>>>>>> users that use thin clients to connect to a remote Windows device >>>>>>>> which is >>>>>>>> often running in a VM without access to a physical GPU. >>>>>>>> >>>>>>>> For example, this applies to the Microsoft Dev Box offering ( >>>>>>>> https://azure.microsoft.com/en-us/products/dev-box/). >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> Unfortunately, enterprise clients often turn off telemetry. So, I >>>>>>>> would assume any UMA-derived metrics to be undercounting the >>>>>>>> population. >>>>>>>> >>>>>>>> It’s likely there are certain line-of-business and/or >>>>>>>> consumer-oriented sites that have a hard dependency on WebGL to be >>>>>>>> fully >>>>>>>> functional. >>>>>>>> >>>>>>>> Have you considered, on Windows, targeting WARP ( >>>>>>>> https://learn.microsoft.com/en-us/windows/win32/direct3darticles/directx-warp) >>>>>>>> >>>>>>>> instead? I don’t know if there are other viable alternatives on other >>>>>>>> OSes, >>>>>>>> but if the primary impacted clients are Windows perhaps that would be >>>>>>>> a >>>>>>>> sufficient mitigation. >>>>>>>> >>>>>>>> To help enterprise customers reason about how much this is going to >>>>>>>> impact them, it would be helpful to have an enterprise policy to >>>>>>>> control >>>>>>>> this. This is a common pattern for potentially high-impact changes. >>>>>>>> >>>>>>>> In its initial phase, the policy would enable motivated enterprises >>>>>>>> to forcibly disable SwiftShader as a scream test. And after you switch >>>>>>>> over >>>>>>>> the default, it could enable enterprises caught unaware to have some >>>>>>>> additional window of time to plan mitigations (by re-enabling it via >>>>>>>> policy) before you proceed with fully deprecating support and remove >>>>>>>> the >>>>>>>> policy. >>>>>>>> >>>>>>>> Can you comment on if you plan to add such a policy or, if not, why >>>>>>>> not? >>>>>>>> >>>>>>>> Thanks! >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> *From:* 'Ashley Gullen' via blink-dev <blin...@chromium.org> >>>>>>>> *Sent:* Thursday, February 27, 2025 4:14 AM >>>>>>>> *To:* Rick Byers <rby...@chromium.org> >>>>>>>> *Cc:* David Adrian <dad...@google.com>; blink-dev < >>>>>>>> blin...@chromium.org>; geof...@chromium.org <geof...@chromium.org> >>>>>>>> *Subject:* [EXTERNAL] Re: [blink-dev] Intent to Remove: >>>>>>>> SwiftShader Fallback >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> Thanks for the response Rick, I agree with much of what you've said >>>>>>>> and I think your views and suggested workarounds are all generally >>>>>>>> reasonable. >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> I just realised I previously responded to this thread but only >>>>>>>> replied to David - for transparency I've copied my previous response >>>>>>>> below. >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> I can confirm all content made with Construct since about 2018 >>>>>>>> requires WebGL to work and will show an error message if WebGL is >>>>>>>> unavailable. I've included a screenshot of the message Construct >>>>>>>> content >>>>>>>> published to the web will display when WebGL is not supported, saying >>>>>>>> "Software update needed", since that has usually been the best advice >>>>>>>> in >>>>>>>> that situation in the past. As my previous message says we long ago >>>>>>>> removed >>>>>>>> any other fallback and are now likely too dependent on WebGL to >>>>>>>> feasibly >>>>>>>> reimplement a canvas2d fallback. >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> Some other thoughts about workarounds/mitigations: >>>>>>>> >>>>>>>> - A swiftshader WASM module would at least give us a >>>>>>>> workaround, but if that was something like a ~10 MB+ module it >>>>>>>> would be a >>>>>>>> very high download overhead which we'd be obligated to include in >>>>>>>> every >>>>>>>> Construct export for compatibility >>>>>>>> - Swiftshader could be removed from insecure origins with >>>>>>>> little impact to us, and using a permission policy for cross-site >>>>>>>> iframes >>>>>>>> should be straightforward to work with >>>>>>>> - If it helps reduce the attack surface, we could live with >>>>>>>> SwiftShader support for WebGL 1 only (no WebGL 2) with minimum >>>>>>>> capabilities >>>>>>>> (no extensions). >>>>>>>> - A permission prompt to the user is not ideal but better than >>>>>>>> nothing, and I imagine it would be tricky to explain to a normal >>>>>>>> web user >>>>>>>> though the prompt message (and makes obtaining a WebGL context >>>>>>>> async...) >>>>>>>> - Regarding getting WebGL to work on more devices, as I >>>>>>>> mentioned in my previous message, reviewing the GPU blocklist to >>>>>>>> re-enable >>>>>>>> WebGL for older devices if drivers have been updated or workarounds >>>>>>>> for >>>>>>>> issues can be found would help reduce the number of devices subject >>>>>>>> to >>>>>>>> SwiftShader. Being able to enable at least WebGL 1 will still help >>>>>>>> with >>>>>>>> Construct content. >>>>>>>> - If a software fallback can be securely implemented for >>>>>>>> WebGPU, Construct has a WebGPU renderer too now so that would give >>>>>>>> us a >>>>>>>> workaround (and potentially for any other WebGL content - AFAIK >>>>>>>> many widely >>>>>>>> used libraries like three.js now either support WebGPU or are >>>>>>>> working on it) >>>>>>>> >>>>>>>> Thanks for the consideration all. >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> Copy of my previous message: >>>>>>>> >>>>>>>> ----- >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> OK, thanks for the information. I just want to point out that even >>>>>>>> stopping WebGL content for only 2.7% of users is still potentially >>>>>>>> very >>>>>>>> disruptive. Consider a web game on Poki that requires WebGL and gets a >>>>>>>> million players. With this change, now 27,000 users will see a "WebGL >>>>>>>> not >>>>>>>> supported" error message. That's then potentially a huge number of new >>>>>>>> support requests to deal with. >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> > Can you share the number for Construct about what percentage of >>>>>>>> your users are using the SwiftShader fallback? Again, our numbers >>>>>>>> indicate >>>>>>>> that these are primarily older Windows workstations. >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> For the Construct editor itself, it is around 3%, so that seems in >>>>>>>> line. But the key point here is that Construct is middleware: it is a >>>>>>>> tool >>>>>>>> our users develop web games in and then publish independently of us. >>>>>>>> It is >>>>>>>> much more important that WebGL works for players of those games than >>>>>>>> it >>>>>>>> does for Construct itself. >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> Lots of people use older Windows workstations. We've had issues >>>>>>>> before where for example a graphics driver bug affecting WebGL 1 >>>>>>>> caused a >>>>>>>> great deal of trouble in a South American market, even though I >>>>>>>> suspect it >>>>>>>> only affected a small percentage of devices - see >>>>>>>> https://issues.chromium.org/issues/40941645 which was never >>>>>>>> resolved. There are probably places in the world where there are large >>>>>>>> numbers of people using older Windows workstations. I fear that >>>>>>>> pulling >>>>>>>> WebGL support from those devices may result in much higher numbers of >>>>>>>> unsupported users, and many more support requests, in the specific >>>>>>>> markets >>>>>>>> where such devices are common. >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> Is there anything that can be done to mitigate this change? Given >>>>>>>> SwiftShader allowed WebGL to be considered ubiquitous for many years, >>>>>>>> engines like Construct long ago removed any fallback for systems that >>>>>>>> do >>>>>>>> not support WebGL; we moved forward assuming we could rely on WebGL, >>>>>>>> and so >>>>>>>> now it's probably infeasible to bring back any fallback as we have too >>>>>>>> many >>>>>>>> key features that fundamentally require WebGL. Could SwiftShader be >>>>>>>> adapted >>>>>>>> to not use JIT? Could some other fallback be found? Could the GPU >>>>>>>> blocklist >>>>>>>> be revised to enable WebGL on as many older devices as possible? >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> I think the number of affected users should be <1% to minimise the >>>>>>>> impact from such a change. At web scale 2.7% is still a lot. Perhaps >>>>>>>> with >>>>>>>> revising the GPU blocklist and adding more workarounds this is >>>>>>>> feasible. I >>>>>>>> fear if this goes ahead without any mitigation, it will cause a great >>>>>>>> deal >>>>>>>> of trouble and is exactly the kind of thing sceptics of the web will >>>>>>>> bring >>>>>>>> up to say that web technology sucks, browsers can't be trusted, and >>>>>>>> people >>>>>>>> should just develop desktop games instead. >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> On Tue, 25 Feb 2025 at 22:31, Rick Byers <rby...@chromium.org> >>>>>>>> wrote: >>>>>>>> >>>>>>>> Sorry for the delay from API owners, as discussed on chat the >>>>>>>> chromestatus entry wasn't set up properly to request API owner review >>>>>>>> (now >>>>>>>> fixed). >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> This is a tricky one indeed (thanks for your input Ashley!). It looks >>>>>>>> like >>>>>>>> <https://chromestatus.com/metrics/feature/timeline/popularity/4026> >>>>>>>> WebGL is used on about 20% of page loads, so 2.7% of that is ~0.5% of >>>>>>>> page >>>>>>>> loads which is very high risk according to our rules of thumb >>>>>>>> <https://docs.google.com/document/d/1RC-pBBvsazYfCNNUSkPqAVpSpNJ96U8trhNkfV0v9fk/edit?tab=t.0#heading=h.mqfkui78vo5z> >>>>>>>> . >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> Of course that's an upper-bound, how many will have a fallback? One >>>>>>>> option would be to collect some UKM data for SwiftShader usage and >>>>>>>> review a >>>>>>>> random ~50 sites to observe the user experience in practice. That >>>>>>>> could >>>>>>>> give us a better sense of what the real user impact would likely be. >>>>>>>> Or >>>>>>>> Maybe Ashley can give us some examples of some web games just to >>>>>>>> confirm >>>>>>>> they indeed go from being playable to unplayable without swiftshader >>>>>>>> on >>>>>>>> some specific devices? David, do you have a device yourself you can >>>>>>>> test >>>>>>>> with that doesn't support GPU WebGL? >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> Regardless, unless sites have been really good about almost always >>>>>>>> falling back somehow, I suspect we'll find that there's enough >>>>>>>> end-user >>>>>>>> impact to make this a high-risk change (but I could be convinced >>>>>>>> otherwise >>>>>>>> such as via a thorough UKM analysis). In which case then we could >>>>>>>> start >>>>>>>> working through our playbook for a phased plan for risky breaking >>>>>>>> changes. >>>>>>>> Not unlike what we did for flash removal >>>>>>>> <https://www.chromium.org/flash-roadmap/>, or WebSQL >>>>>>>> <https://developer.chrome.com/blog/deprecating-web-sql> (both big >>>>>>>> security benefit but big web compat risk). For example: >>>>>>>> >>>>>>>> - Explore whether we can build swiftshader into a wasm module >>>>>>>> that sites can use as a (probably even slower) fallback themselves. >>>>>>>> This >>>>>>>> turned out to be the key to making WebSQL deprecation tractable. In >>>>>>>> general >>>>>>>> our policy >>>>>>>> >>>>>>>> <https://docs.google.com/document/d/1RC-pBBvsazYfCNNUSkPqAVpSpNJ96U8trhNkfV0v9fk/edit?tab=t.0#heading=h.x5bhg5grhfeo> >>>>>>>> >>>>>>>> is that we don't take functionality away that developers can't >>>>>>>> replace with >>>>>>>> some other substitute except in pretty extreme circumstances. >>>>>>>> - Prompt the user on whether or not to enable it per-origin >>>>>>>> (like a permission) >>>>>>>> - Put 3p usage behind a permission policy so the top-level site >>>>>>>> has to opt-in to allow 3p iframes to use swiftshader >>>>>>>> - Rely on some heuristics, (perhaps crowd-sourced signals) to >>>>>>>> try to find a sweet spot in the safety vs. functionality tradeoff >>>>>>>> space. We >>>>>>>> did this for flash initially with things like blocking it for very >>>>>>>> small >>>>>>>> canvases. >>>>>>>> - Anything we can do to make WebGL work on a larger set of >>>>>>>> devices? >>>>>>>> - Probably lots of other ideas that aren't occurring to me >>>>>>>> right now, more examples in bit.ly/blink.compat. >>>>>>>> >>>>>>>> On the other side of the equation, API owners can be convinced to >>>>>>>> accept more compat risk the more significant the security benefits >>>>>>>> are. Are >>>>>>>> there more details you can share? Such as: >>>>>>>> >>>>>>>> - Are we confident that an attacker can only trigger >>>>>>>> swiftshader on somewhere around 3% of users (vs. some knob which >>>>>>>> can force >>>>>>>> it to be used on a larger fraction)? To what extent do we have >>>>>>>> reason to >>>>>>>> believe that the vulnerable population size is large enough to be a >>>>>>>> plausible target for attackers? Is there anything we can do to make >>>>>>>> the >>>>>>>> vulnerable user base more reliably contained? >>>>>>>> - How does swiftshader compare to other areas in terms of the >>>>>>>> number of vulnerabilities we've found in practice? Are there any >>>>>>>> reports of >>>>>>>> ITW exploits of it? It looks like >>>>>>>> >>>>>>>> <https://chrome-commit-tracker.arthursonzogni.com/cve/reward_per_components?start=2019-12-27&end=2025-02-25> >>>>>>>> >>>>>>>> since 2020 SwiftShader has been about 8% of Chrome's VRP spend - >>>>>>>> that seems >>>>>>>> quite significant to me, but probably not in the top 5 areas of >>>>>>>> concern. >>>>>>>> This was obviously key to the immense cost and pain of Flash >>>>>>>> removal - we >>>>>>>> kept having severe security incidents in practice. >>>>>>>> >>>>>>>> So assuming Ashley and I are right that this isn't likely to be >>>>>>>> easy, that means it's likely quite a lot of work to attempt to >>>>>>>> phase-out >>>>>>>> SwiftShader in a responsible fashion. But with luck maybe we can find >>>>>>>> a >>>>>>>> first step that is a good cost-benefit tradeoff (like putting 3P usage >>>>>>>> behind a permission prompt)? Or maybe it's just a better cost-benefit >>>>>>>> tradeoff to invest in other areas which pose a threat to a greater >>>>>>>> number >>>>>>>> users (hardening ANGLE perhaps)? But of course I will defer to the >>>>>>>> judgement of security and GPU experts like yourself on that question, >>>>>>>> I'm >>>>>>>> happy to consult and support if you want to invest in a plan that API >>>>>>>> owners can approve. >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> Rick >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> On Wed, Feb 19, 2025 at 2:48 PM 'David Adrian' via blink-dev < >>>>>>>> blin...@chromium.org> wrote: >>>>>>>> >>>>>>>> > I wrote about this previously but I'm still concerned this is a >>>>>>>> major breaking change for existing published WebGL content on the web. >>>>>>>> If >>>>>>>> the figure of 2.7% comes from my previous citing of Web3DSurvey >>>>>>>> >>>>>>>> It does, not it comes from Chrome's metrics system. >>>>>>>> >>>>>>>> > Does Google have their own internal data about the usage of >>>>>>>> SwiftShader? >>>>>>>> >>>>>>>> It is the 2.7% number. >>>>>>>> >>>>>>>> > Suppose this change rolls out and we get reports that say our >>>>>>>> WebGL content no longer works for 10% of users in a South American >>>>>>>> market. >>>>>>>> Then what? There is nothing feasible we can do about it. These >>>>>>>> customers >>>>>>>> were previously getting by with SwiftShader, but now they get an error >>>>>>>> message. So I fear this risks disaster for web games in some markets. >>>>>>>> >>>>>>>> > I mentioned I don't think it should be used as evidence to make >>>>>>>> such a big change as this. Maybe in some places it will affect 25% or >>>>>>>> 50% >>>>>>>> of users - who knows? How can we be sure? >>>>>>>> >>>>>>>> Can you share the number for Construct about what percentage of >>>>>>>> your users are using the SwiftShader fallback? Again, our numbers >>>>>>>> indicate >>>>>>>> that these are primarily older Windows workstations. Notably, >>>>>>>> SwiftShader >>>>>>>> is not used at all on mobile. >>>>>>>> >>>>>>>> > V8 does JIT with untrusted JavaScript code and that is generally >>>>>>>> considered reasonably secure, is there any particular technical reason >>>>>>>> SwiftShader is not considered as secure? >>>>>>>> >>>>>>>> Yes. The GPU process is shared between all sites, whereas the V8 >>>>>>>> JIT is per-site. This means compromising the GPU process can be enough >>>>>>>> to >>>>>>>> bypass site isolation protections with a single bug. Additionally, V8 >>>>>>>> bugs >>>>>>>> can be reliably patched in the browser, whereas SwiftShader "bugs" can >>>>>>>> be >>>>>>>> user-mode graphics driver bugs that are simply more exposed via >>>>>>>> SwiftShader >>>>>>>> than they would be otherwise. In this case, the browser can't patch >>>>>>>> the bug >>>>>>>> because it's in the driver. >>>>>>>> >>>>>>>> >>>>>>>> On Thursday, February 13, 2025 at 12:12:07 PM UTC-5 >>>>>>>> ash...@scirra.com wrote: >>>>>>>> >>>>>>>> I wrote about this previously but I'm still concerned this is a >>>>>>>> major breaking change for existing published WebGL content on the web. >>>>>>>> If >>>>>>>> the figure of 2.7% comes from my previous citing of Web3DSurvey ( >>>>>>>> https://web3dsurvey.com/) then this should be seen as very much an >>>>>>>> underestimate, because that site uses a relatively small sample size >>>>>>>> that >>>>>>>> is more likely to be focused on high-end devices (samples are taken >>>>>>>> from >>>>>>>> developer-focused sites like the three.js website, WebGPU fundamentals >>>>>>>> etc). I would not be surprised if the real worldwide average was more >>>>>>>> like >>>>>>>> 4-5%. Then if that's a worldwide average, there will probably be some >>>>>>>> specific countries or markets where the figure could be more like 10%. >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> Suppose this change rolls out and we get reports that say our WebGL >>>>>>>> content no longer works for 10% of users in a South American market. >>>>>>>> Then >>>>>>>> what? There is nothing feasible we can do about it. These customers >>>>>>>> were >>>>>>>> previously getting by with SwiftShader, but now they get an error >>>>>>>> message. >>>>>>>> So I fear this risks disaster for web games in some markets. >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> Does Google have their own internal data about the usage of >>>>>>>> SwiftShader? Can more data about this be shared? I respect the work >>>>>>>> done by >>>>>>>> Web3DSurvey but unfortunately for the reasons I mentioned I don't >>>>>>>> think it >>>>>>>> should be used as evidence to make such a big change as this. Maybe in >>>>>>>> some >>>>>>>> places it will affect 25% or 50% of users - who knows? How can we be >>>>>>>> sure? >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> Can there not be some other fallback implemented? V8 does JIT with >>>>>>>> untrusted JavaScript code and that is generally considered reasonably >>>>>>>> secure, is there any particular technical reason SwiftShader is not >>>>>>>> considered as secure? >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> I'd also point out that any website that has a poor experience with >>>>>>>> SwiftShader can already opt-out using the failIfMajorPerformanceCaveat >>>>>>>> context flag. If there is some other mode that can be used instead, or >>>>>>>> just >>>>>>>> showing an error message is acceptable, then websites can already >>>>>>>> implement >>>>>>>> that. In our case with Construct we specifically attempt to obtain >>>>>>>> hardware-accelerated WebGPU, WebGL 2, or WebGL 1; only failing that do >>>>>>>> we >>>>>>>> resort to using SwiftShader on the basis that showing the content with >>>>>>>> potentially poor performance is better than not showing it at all. >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> On Thu, 13 Feb 2025 at 15:46, 'David Adrian' via blink-dev < >>>>>>>> blin...@chromium.org> wrote: >>>>>>>> >>>>>>>> Contact emails >>>>>>>> >>>>>>>> dad...@google.com, geof...@chromium.org >>>>>>>> >>>>>>>> >>>>>>>> Summary >>>>>>>> >>>>>>>> Allowing automatic fallback to WebGL backed by SwiftShader is >>>>>>>> deprecated and will be removed. This has been noted in DevTools since >>>>>>>> Chrome 130. >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> WebGL context creation will fail instead of falling back to >>>>>>>> SwiftShader. This is for two primary reasons: >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> 1. SwiftShader is a high security risk due to JIT-ed code running >>>>>>>> in Chromium's GPU process. >>>>>>>> >>>>>>>> 2. Users have a poor experience when falling back from a >>>>>>>> high-performance GPU-backed WebGL to a CPU-backed implementation. >>>>>>>> Users >>>>>>>> have no control over this behavior and it is difficult to describe in >>>>>>>> bug >>>>>>>> reports. >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> SwiftShader is a useful tool for web developers to test their sites >>>>>>>> on systems that are headless or do not have a supported GPU. This use >>>>>>>> case >>>>>>>> will still be supported by opting in but is not intended for running >>>>>>>> untrusted content. >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> To opt-in to lower security guarantees and allow SwiftShader for >>>>>>>> WebGL, run the chrome executable with the --enable-unsafe-swiftshader >>>>>>>> command-line switch. >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> During the deprecation period, a warning will appear in the >>>>>>>> javascript console when a WebGL context is created and backed with >>>>>>>> SwiftShader. Passing --enable-unsafe-swiftshader will remove this >>>>>>>> warning >>>>>>>> message. This deprecation period began in Chrome 130. >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> Chromium and other browsers do not guarantee WebGL availability. >>>>>>>> Please test and handle WebGL context creation failure and fall back to >>>>>>>> other web APIs such as Canvas2D or an appropriate message to the user. >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> SwiftShader is an internal implementation detail of Chromium, not a >>>>>>>> public web standard, therefore buy-in from other browsers is not >>>>>>>> required. >>>>>>>> The devices covered by SwiftShader (primarily older Windows devices) >>>>>>>> are >>>>>>>> likely already incompatible with WebGL in other browsers. >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> SwiftShader is not used on mobile; this only applies to Desktop >>>>>>>> platforms. >>>>>>>> >>>>>>>> >>>>>>>> Blink component >>>>>>>> >>>>>>>> Blink>WebGL >>>>>>>> <https://issues.chromium.org/issues?q=customfield1222907:%22Blink%3EWebGL%22> >>>>>>>> >>>>>>>> >>>>>>>> Motivation >>>>>>>> >>>>>>>> >>>>>>>> https://chromium.googlesource.com/chromium/src/+/main/docs/gpu/swiftshader.md#automatic-swiftshader-webgl-fallback-is-deprecated >>>>>>>> >>>>>>>> >>>>>>>> Risks >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> SwiftShader is used by devices without hardware acceleration for >>>>>>>> WebGL. This is approximately 2.7% of WebGL contexts. However, WebGL is >>>>>>>> considered fallible and in many cases, these draws are not performant >>>>>>>> and >>>>>>>> provide an effectively unusable experience for users. Many >>>>>>>> applications, >>>>>>>> such as Google Maps, prefer to fail out rather than use SwiftShader. >>>>>>>> >>>>>>>> >>>>>>>> Debuggability >>>>>>>> >>>>>>>> None >>>>>>>> >>>>>>>> >>>>>>>> Flag name on about://flags >>>>>>>> >>>>>>>> --enable-unsafe-swiftshader command-line switch. >>>>>>>> >>>>>>>> >>>>>>>> Finch feature name >>>>>>>> >>>>>>>> AllowSwiftShaderFallback >>>>>>>> >>>>>>>> >>>>>>>> Tracking bug >>>>>>>> >>>>>>>> https://issues.chromium.org/40277080 >>>>>>>> >>>>>>>> >>>>>>>> Launch bug >>>>>>>> >>>>>>>> https://launch.corp.google.com/launch/4351104 >>>>>>>> >>>>>>>> >>>>>>>> Estimated milestones >>>>>>>> >>>>>>>> Shipping on Desktop 137 >>>>>>>> >>>>>>>> >>>>>>>> Link to entry on the Chrome Platform Status >>>>>>>> >>>>>>>> >>>>>>>> https://chromestatus.com/feature/5166674414927872?gate=5188866041184256 >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> This intent message was generated by Chrome Platform Status >>>>>>>> <https://chromestatus.com/>. >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> -- >>>>>>>> You received this message because you are subscribed to the Google >>>>>>>> Groups "blink-dev" group. >>>>>>>> To unsubscribe from this group and stop receiving emails from it, >>>>>>>> send an email to blink-dev+...@chromium.org. >>>>>>>> To view this discussion visit >>>>>>>> https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CAGkh42KV4DrSSyEgJaF4DnFOXAye-wRLrfD-LKGNkWhyWzshLA%40mail.gmail.com >>>>>>>> >>>>>>>> <https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CAGkh42KV4DrSSyEgJaF4DnFOXAye-wRLrfD-LKGNkWhyWzshLA%40mail.gmail.com?utm_medium=email&utm_source=footer> >>>>>>>> . >>>>>>>> >>>>>>>> -- >>>>>>>> You received this message because you are subscribed to the Google >>>>>>>> Groups "blink-dev" group. >>>>>>>> To unsubscribe from this group and stop receiving emails from it, >>>>>>>> send an email to blink-dev+...@chromium.org. >>>>>>>> To view this discussion visit >>>>>>>> https://groups.google.com/a/chromium.org/d/msgid/blink-dev/c5131675-dff4-4aa0-8e84-4cdc373e3035n%40chromium.org >>>>>>>> >>>>>>>> <https://groups.google.com/a/chromium.org/d/msgid/blink-dev/c5131675-dff4-4aa0-8e84-4cdc373e3035n%40chromium.org?utm_medium=email&utm_source=footer> >>>>>>>> . >>>>>>>> >>>>>>>> -- >>>>>>>> You received this message because you are subscribed to the Google >>>>>>>> Groups "blink-dev" group. >>>>>>>> To unsubscribe from this group and stop receiving emails from it, >>>>>>>> send an email to blink-dev+...@chromium.org. >>>>>>>> To view this discussion visit >>>>>>>> https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CAABs73jWBkuxvj%3DDDXmEQNwLfCa_uV5OZZ5nZJRj9ZMgP9yk7Q%40mail.gmail.com >>>>>>>> >>>>>>>> <https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CAABs73jWBkuxvj%3DDDXmEQNwLfCa_uV5OZZ5nZJRj9ZMgP9yk7Q%40mail.gmail.com?utm_medium=email&utm_source=footer> >>>>>>>> . >>>>>>>> >>>>>>>> -- >>>>>>>> You received this message because you are subscribed to the Google >>>>>>>> Groups "blink-dev" group. >>>>>>>> To unsubscribe from this group and stop receiving emails from it, >>>>>>>> send an email to blink-dev+...@chromium.org. >>>>>>>> To view this discussion visit >>>>>>>> https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CAABs73hYs9O-2hdmfn37fQb-U-8m_-08i3Qg9dkUhKNQQvNLSg%40mail.gmail.com >>>>>>>> >>>>>>>> <https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CAABs73hYs9O-2hdmfn37fQb-U-8m_-08i3Qg9dkUhKNQQvNLSg%40mail.gmail.com?utm_medium=email&utm_source=footer> >>>>>>>> . >>>>>>>> >>>>>>>> -- You received this message because you are subscribed to the Google Groups "blink-dev" group. To unsubscribe from this group and stop receiving emails from it, send an email to blink-dev+unsubscr...@chromium.org. To view this discussion visit https://groups.google.com/a/chromium.org/d/msgid/blink-dev/bf7c2f1f-0496-40cf-bd3e-b92e60a61facn%40chromium.org.
