Messages in this thread | | | Date | Tue, 31 May 2022 11:04:05 -0700 | From | Kees Cook <> | Subject | Re: [PATCH v2 3/8] KVM: x86: Omit VCPU_REGS_RIP from emulator's _regs array |
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On Thu, May 26, 2022 at 09:08:12PM +0000, Sean Christopherson wrote: > Omit RIP from the emulator's _regs array, which is used only for GPRs, > i.e. registers that can be referenced via ModRM and/or SIB bytes. The > emulator uses the dedicated _eip field for RIP, and manually reads from > _eip to handle RIP-relative addressing. > > To avoid an even bigger, slightly more dangerous change, hardcode the > number of GPRs to 16 for the time being even though 32-bit KVM's emulator > technically should only have 8 GPRs. Add a TODO to address that in a > future commit. > > See also the comments above the read_gpr() and write_gpr() declarations, > and obviously the handling in writeback_registers(). > > No functional change intended. > > Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
-- Kees Cook
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