We are dangerously close to the array limits in kvm_put_msrs()
and kvm_get_msrs(): with the default mcg_cap configuration, we
can set up to 148 MSRs in kvm_put_msrs(), and if we allow mcg_cap
to be changed, we can write up to 236 MSRs[1].
This series changes the code to allocate a buffer once per VCPU,
increase buffer size to 4096 bytes (that can hold up to 255 MSR
entries), and check array limits before appending new entries.
[1] I have checked the limits by copying and pasting the
kvm_put_msrs() code to a new file, replacing the "if" lines,
copying the macro definitions, and adding a helper macro to
keep track of the kvm_msr_entry_set() calls. The code can be
seen at:
https://gist.github.com/ehabkost/08d4177a33b8648a71ef
Eduardo Habkost (5):
target-i386: kvm: Allocate kvm_msrs struct once per VCPU
target-i386: kvm: Increase MSR_BUF_SIZE
target-i386: kvm: Simplify MSR array construction
target-i386: kvm: Simplify MSR setting functions
target-i386: kvm: Eliminate kvm_msr_entry_set()
target-i386/cpu-qom.h | 4 +
target-i386/kvm.c | 322 +++++++++++++++++++++++---------------------------
2 files changed, 149 insertions(+), 177 deletions(-)
--
2.1.0
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