Re: [PATCH v5 11/19] KVM:VMX: Emulate read and write to CET MSRs

From: Yang, Weijiang
Date: Wed Aug 09 2023 - 03:12:44 EST


On 8/4/2023 4:28 PM, Chao Gao wrote:
+ case MSR_IA32_PL0_SSP ... MSR_IA32_INT_SSP_TAB:
+ if (!kvm_cet_is_msr_accessible(vcpu, msr_info))
+ return 1;
+ if (is_noncanonical_address(data, vcpu))
+ return 1;
+ if (!IS_ALIGNED(data, 4))
+ return 1;
Why should MSR_IA32_INT_SSP_TAB be 4-byte aligned? I don't see
this requirement in SDM.
It must be something wrong in my memory, thanks for catching it!
IA32_INTERRUPT_SSP_TABLE_ADDR:

Linear address of a table of seven shadow
stack pointers that are selected in IA-32e
mode using the IST index (when not 0) from
the interrupt gate descriptor. (R/W)
This MSR is not present on processors that
do not support Intel 64 architecture. This
field cannot represent a non-canonical
address.