fix(whp): respect IO port access size in IoPortAccess exit handler#1387
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jprendes merged 1 commit intohyperlight-dev:mainfrom Apr 17, 2026
Merged
fix(whp): respect IO port access size in IoPortAccess exit handler#1387jprendes merged 1 commit intohyperlight-dev:mainfrom
jprendes merged 1 commit intohyperlight-dev:mainfrom
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The WHP IoPortAccess exit handler was returning the full 8 bytes of RAX regardless of the guest's operand width. For outb (1-byte writes like serial port console output), this produced 8 bytes per character, resulting in garbled multi-byte sequences in the host's eprint! output. Extract AccessSize from IoPortAccess.AccessInfo (bits 1..3) and truncate the returned data vec to the actual operand width (1 for outb, 2 for outw, 4 for outl). Signed-off-by: danbugs <danilochiarlone@gmail.com>
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Summary
IoPortAccessexit handler was returning the full 8 bytes of RAX regardless of the guest's operand widthoutb(1-byte writes like serial console output), this produced 8 bytes per character, resulting in garbled multi-byte sequences in the host outputAccessSizefromIoPortAccess.AccessInfo(bits 1..3) and truncate the returned data vec to the actual operand width (1 for outb, 2 for outw, 4 for outl)