Date: Sat, 20 Sep 2014 05:12:35 +0000 (UTC) From: Neel Natu <neel@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r271890 - head/sys/amd64/vmm/intel Message-ID: <201409200512.s8K5CZEH070080@svn.freebsd.org>
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Author: neel Date: Sat Sep 20 05:12:34 2014 New Revision: 271890 URL: http://svnweb.freebsd.org/changeset/base/271890 Log: MSR_KGSBASE is no longer saved and restored from the guest MSR save area. This behavior was changed in r271888 so update the comment block to reflect this. MSR_KGSBASE is accessible from the guest without triggering a VM-exit. The permission bitmap for MSR_KGSBASE is modified by vmx_msr_guest_init() so get rid of redundant code in vmx_vminit(). Modified: head/sys/amd64/vmm/intel/vmx.c Modified: head/sys/amd64/vmm/intel/vmx.c ============================================================================== --- head/sys/amd64/vmm/intel/vmx.c Sat Sep 20 04:31:12 2014 (r271889) +++ head/sys/amd64/vmm/intel/vmx.c Sat Sep 20 05:12:34 2014 (r271890) @@ -885,12 +885,6 @@ vmx_vminit(struct vm *vm, pmap_t pmap) * how they are saved/restored so can be directly accessed by the * guest. * - * Guest KGSBASE is saved and restored in the guest MSR save area. - * Host KGSBASE is restored before returning to userland from the pcb. - * There will be a window of time when we are executing in the host - * kernel context with a value of KGSBASE from the guest. This is ok - * because the value of KGSBASE is inconsequential in kernel context. - * * MSR_EFER is saved and restored in the guest VMCS area on a * VM exit and entry respectively. It is also restored from the * host VMCS area on a VM exit. @@ -905,7 +899,6 @@ vmx_vminit(struct vm *vm, pmap_t pmap) guest_msr_rw(vmx, MSR_SYSENTER_CS_MSR) || guest_msr_rw(vmx, MSR_SYSENTER_ESP_MSR) || guest_msr_rw(vmx, MSR_SYSENTER_EIP_MSR) || - guest_msr_rw(vmx, MSR_KGSBASE) || guest_msr_rw(vmx, MSR_EFER) || guest_msr_ro(vmx, MSR_TSC)) panic("vmx_vminit: error setting guest msr access");
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