forked from SLFO-pool/xen
35 lines
1.2 KiB
Diff
35 lines
1.2 KiB
Diff
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# Commit 4fdd8d75566fdad06667a79ec0ce6f43cc466c54
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# Date 2024-06-13 16:55:22 +0200
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# Author Jan Beulich <jbeulich@suse.com>
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# Committer Jan Beulich <jbeulich@suse.com>
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x86/EPT: drop questionable mfn_valid() from epte_get_entry_emt()
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mfn_valid() is RAM-focused; it will often return false for MMIO. Yet
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access to actual MMIO space should not generally be restricted to UC
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only; especially video frame buffer accesses are unduly affected by such
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a restriction.
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Since, as of 777c71d31325 ("x86/EPT: avoid marking non-present entries
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for re-configuring"), the function won't be called with INVALID_MFN or,
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worse, truncated forms thereof anymore, we call fully drop that check.
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Fixes: 81fd0d3ca4b2 ("x86/hvm: simplify 'mmio_direct' check in epte_get_entry_emt()")
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Signed-off-by: Jan Beulich <jbeulich@suse.com>
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Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
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--- a/xen/arch/x86/mm/p2m-ept.c
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+++ b/xen/arch/x86/mm/p2m-ept.c
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@@ -500,12 +500,6 @@ int epte_get_entry_emt(struct domain *d,
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return -1;
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}
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- if ( !mfn_valid(mfn) )
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- {
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- *ipat = true;
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- return X86_MT_UC;
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- }
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-
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/*
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* Conditional must be kept in sync with the code in
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* {iomem,ioports}_{permit,deny}_access().
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