On 27.04.2022 05:46, Tian, Kevin wrote: >> From: Lengyel, Tamas <[email protected]> >> Sent: Friday, March 25, 2022 9:33 PM >> >> During VM forking and resetting a failed vmentry has been observed due >> to the guest non-register state going out-of-sync with the guest register >> state. For example, a VM fork reset right after a STI instruction can trigger >> the failed entry. This is due to the guest non-register state not being saved >> from the parent VM, thus the reset operation only copies the register state. >> >> Fix this by adding a new pair of hvm functions to get/set the guest >> non-register state so that the overall vCPU state remains in sync. >> >> Signed-off-by: Tamas K Lengyel <[email protected]> > > Reviewed-by: Kevin Tian <[email protected]>
Acked-by: Jan Beulich <[email protected]> with ... >> @@ -863,6 +892,17 @@ static inline void hvm_set_reg(struct vcpu *v, >> unsigned int reg, uint64_t val) >> ASSERT_UNREACHABLE(); >> } >> >> +static inline void hvm_get_nonreg_state(struct vcpu *v, >> + struct hvm_vcpu_nonreg_state *nrs) >> +{ >> + ASSERT_UNREACHABLE(); >> +} >> +static inline void hvm_set_nonreg_state(struct vcpu *v, >> + struct hvm_vcpu_nonreg_state *nrs) >> +{ >> + ASSERT_UNREACHABLE(); >> +} ... these unnecessary stubs dropped (they should be introduced only once actually needed, i.e. when a caller appears in a file which is also built when !CONFIG_HVM), and ... >> --- a/xen/arch/x86/mm/mem_sharing.c >> +++ b/xen/arch/x86/mm/mem_sharing.c >> @@ -1643,6 +1643,13 @@ static int bring_up_vcpus(struct domain *cd, >> struct domain *d) >> return 0; >> } >> >> +static void copy_vcpu_nonreg_state(struct vcpu *d_vcpu, struct vcpu >> *cd_vcpu) >> +{ >> + struct hvm_vcpu_nonreg_state nrs = {}; >> + hvm_get_nonreg_state(d_vcpu, &nrs); ... this missing blank line inserted between these two lines. I'll make both adjustments while committing. Jan
