[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [PATCH v2] x86emul: de-duplicate scatters to the same linear address
- To: Jan Beulich <jbeulich@xxxxxxxx>
- From: Roger Pau Monné <roger.pau@xxxxxxxxxx>
- Date: Mon, 18 Oct 2021 13:19:55 +0200
- Arc-authentication-results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=citrix.com; dmarc=pass action=none header.from=citrix.com; dkim=pass header.d=citrix.com; arc=none
- Arc-message-signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector9901; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-AntiSpam-MessageData-ChunkCount:X-MS-Exchange-AntiSpam-MessageData-0:X-MS-Exchange-AntiSpam-MessageData-1; bh=+PpxqIBmpSYx4p5gA0OY+PQaWpWDoOllj221jJ+5rHI=; b=kbuT1EgvDZd4LgmggbREUoi8gA9ZryNoeDqdgXPB5TC/QmV9R2zUQ4WFMeBnTZ+tXAw0WVHhumpjLpUpwNQWaakX9ujt87fiuF59gjruW+ACfBdzc8d+QaleXFyD1wCeE4wJMFOkclGKA/mfWlgwEMZnc5xr9MTvs3DsJJhq4GvOiEU89TT8ehbYTU2TNDglVqNX1tkfgP3S5XBYxkieGdoHmOCpo9IpwMtLmTlXnYb7fSy8nQ4GfB2Lg61p3sBSOvM6ioPrJ4ZDgY0LHtsscWXHlgO1KYPa9mB0N8r8+FRk0VUoP5zPVF2BSOr/BOiWlrySS2gdWhwq8u5Mq51PTw==
- Arc-seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=Z0c4SlDj+sh74yafBKLG1EdN/OclO2KCewJEA7EBd6PeEZuLyrvlHiLFPTY8ZCqBMpZFXJJzYNkqT4Jta/gyo6SGtVzEf3NA9c2AkdHH6nqjFdUiNVq0uxkltQPmfyxof2LS6CJ/pNu9jJfhl1gHJHAKnszxZhmLrW3m0/4X0lOMjaPG87V2rPoWb3L1v8iUMg1WsGBQGYtemAGiTTLkk7wz6nHc/TL9klsu5MDdox+Z5q12CIlpPh6mMrplj2CMD+9w14y5D0lkAxx+QdWW0TNpTGEOe38ydawgRtxG/+3LcEpH/NXnIunU6LoJwmRm1RMgYTQ+HD+ub/K4JSITZw==
- Authentication-results: esa5.hc3370-68.iphmx.com; dkim=pass (signature verified) header.i=@citrix.onmicrosoft.com
- Cc: "xen-devel@xxxxxxxxxxxxxxxxxxxx" <xen-devel@xxxxxxxxxxxxxxxxxxxx>, Andrew Cooper <andrew.cooper3@xxxxxxxxxx>, Wei Liu <wl@xxxxxxx>
- Delivery-date: Mon, 18 Oct 2021 11:20:41 +0000
- Ironport-data: A9a23:sfEls6LE6v6C8HTyFE+RC5IlxSXFcZb7ZxGr2PjKsXjdYENS3zUPy 2IWDGqHPK2IM2ChKN0nbYiwoEoGvZfXz9dhHANlqX01Q3x08seUXt7xwmUcns+xwm8vaGo9s q3yv/GZdJhcokcxIn5BC5C5xZVG/fjgqoHUVaiUZ0ideSc+EH140Eo6y7Zg6mJVqYPR7z2l6 IuaT/L3YDdJ6xYsWo7Dw/vewP/HlK2aVAIw5jTSV9gS1LPtvyB94KYkDbOwNxPFrrx8RYZWc QphIIaRpQs19z91Yj+sfy2SnkciGtY+NiDW4pZatjTLbrGvaUXe345iXMfwZ3u7hB3Xx8Jv+ tdPv6e+WF5uDqqRgc8bSElxRnQW0a1uoNcrIFC6uM2XiUbHb2Ht07NlC0Re0Y8wo7gtRzsUr LpBdW5LPkvra+GemdpXTsF2gcsuNo/zNZ43sXB81zDJS/0hRPgvRo2XuY4Igmlr3KiiG97YS dokdwhEXi7DXCZrEVgYF6gAs8230yyXnzpw9wvO+PtfD3Lo5BN1+KjgNpzSYNPibdVYmAOUq 3zL+0z9AwoGL5qPxDyd6HWui+TT2yThV+o6Fre16/pri1273XEIBVsdUl7TnBWiohfgAZQFc RVSo3dw6/hpnKC2cjXjd0PgsmC2vBwWYNRBSqoK71yU4azPsy/MUwDoUQV9QNAhscY3Qxkj2 VmIg87lCFRTjVGFdZ6O3uzL9W3qaED5OUdHPHVeFVJUvLEPtalq1kqXJuuPBpJZmTEc9dvY+ DuNsDQlz4saicoGxs1XFniW3mry+PAlouMzjzg7v15JDCskPOZJhKTysDA3CMqsyq7DHzFtW 1Bfw6CjABgmV83lqcB0aLxl8EuVz/iEKibAplVkAoMs8T+gk1b6I9sMvGAjdR01bpxVEdMMX KM1kVkAjHO0FCDyBZKbnqrrU5h6pUQePYWNug/ogipmPcEqKV7vENBGbk+MxWH9+HXAYolkU ap3hf2EVC5AYYw+lWLeb75EjdcDm3BvrUuOFMuT50n2jtKjiIu9FO5t3K2mNbtisstpYWz9r r5iCid9404DCbKjPnSOrNd7wJJjBSFTOK0aYvd/L4arCgFnBHsgG7nWx7YgcJZihKNbiqHD+ XTVZ6OS4ACi7ZEeAQnVOH1ldp31WpNz8SAyMSA2ZA760Hk/e4e/qqwYcsJvL7Ug8eViy99yT uUEJJrcUqgeFGyf9mRPd4T5oaxjaA+v2VCEMR26bWVtZJVnXQHIpIPpJ1O96CkUAyOrnsIiu Ln8hBjDSJ8OSl06XsbbYf6i1X2run0ZlL4gVkfEOIALKk7t7JJrO2r6ifpue5MALhDKxz270 QeKAEhH+bmR8tFtqNSQ3PKKtYakFed6D3F2JWiD4ObkLzTe80qi3ZREDLSCcwfCWT6m466lf +hUka3xaaVVgFZQvoNgOL931qZitcD3rrpXwwk4TnXGa1OnVuFpLnWchJQds6RMwvlSuBesW 1LJ8d5fYO3bNMTgGV8XBQwkcuXciq1ExmiMtaw4cBfg+St63LubSkEDbRCDhRtUIKZxLI54k /wqv9Qb6lDnhxcnWjpcYvu4K4hYwqQ8bpga
- Ironport-hdrordr: A9a23:ytVZpqDYlTBRnnDlHeg3sceALOsnbusQ8zAXPh9KJiC9I/b1qy nxppkmPH/P6Qr4WBkb6Le90Y27MAnhHP9OkPIs1NKZMjUO11HYTr2KgbGSpgEIXheOi9K1tp 0QDZSWaueAdGSS5PySiGLTc6dCsai6GeKT9J/jJh9WPH5XgspbnmFE42igYylLrF4sP+tEKH PQ3LsMmxOQPVAsKuirDHgMWObO4/XNiZLdeBYDQzoq8hOHgz+E4KPzV0Hw5GZTbxp/hZMZtU TVmQ3w4auu99m91x/nzmfWq7BbgsHoxNdvDNGFzuIVNjLvoAC1Y5kJYczOgBkF5MWUrHo6mt jFpBkte+x19nPqZ2mw5SDg3gHxuQxeokPK+Bu9uz/OsMb5TDU1B45qnoRCaCbU7EImoZVVzL 9L93jxjesXMTrw2ADGo/TYXRBjkUS55VA4l/QIsnBZWYwCLJdMsI0k+l9PGptoJlO11GkeKp gsMCjg3ocVTbvDBEqp+1WHgebcEUjbJy32AnTr4aeuonxrdHMQ9Tpv+CVQpAZGyHqRI6M0kt gsCZ4Y542mePVmGp6VNN1xMfdfNVa9My4kEFjiaWgPR5t3cE4klfbMkcEIDaeRCdo18Kc=
- Ironport-sdr: J+9a7fkDSHlHMvDhPveA7cpB6qPxXznd9DfnDw0EX/WfFWoftYR/vStqBzQm9IAarzl6kHOpRA P87MVcugIBqmET6njZJ2L3WnN1/hAY9FXCIx7xXYhOB9B9Em754pJN4Ph46VNegSxcLq+FTih8 0geBo7et+P1ta706t9zb2UR/8TOmhnskPR1+FPBH1mdC/ETjUiGytZkgqi4N5fcHXKe87g2/xN sXMeOVJNYNDvV8yiGtTu/Qj0y0PL2R8nJzpyiWnUGQoyY2Vajmt9EnmQlvxyjlkvINBmBcF8wp lvIAr22or0PHBXvR1lg6y1Wk
- List-id: Xen developer discussion <xen-devel.lists.xenproject.org>
On Thu, May 20, 2021 at 03:34:28PM +0200, Jan Beulich wrote:
> The SDM specifically allows for earlier writes to fully overlapping
> ranges to be dropped. If a guest did so, hvmemul_phys_mmio_access()
> would crash it if varying data was written to the same address. Detect
> overlaps early, as doing so in hvmemul_{linear,phys}_mmio_access() would
> be quite a bit more difficult. To maintain proper faulting behavior,
> instead of dropping earlier write instances of fully overlapping slots
> altogether, write the data of the final of these slots multiple times.
Is it possible for a later (non duplicated slot) to cause a fault
ending the instruction without reaching that final slot that contains
the written data?
Thanks, Roger.
|