korg/linux
0
0
Fork 0
mirror of https://mirrors.bfsu.edu.cn/git/linux.git synced 2024-12-30 14:34:51 +08:00
Code Issues Packages Projects Releases Wiki Activity

KVM: SVM: Connect 'npt' module param to KVM's internal 'npt_enabled'

Browse Source 
Directly connect the 'npt' param to the 'npt_enabled' variable so that
runtime adjustments to npt_enabled are reflected in sysfs.  Move the
!PAE restriction to a runtime check to ensure NPT is forced off if the
host is using 2-level paging, and add a comment explicitly stating why
NPT requires a 64-bit kernel or a kernel with PAE enabled.

Opportunistically switch the param to octal permissions.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20210305021637.3768573-1-seanjc@google.com>
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Sean Christopherson 2021-03-04 18:16:37 -08:00 committed by Paolo Bonzini
parent beda430177
commit 99840a7545
1 changed files with 13 additions and 12 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

25
arch/x86/kvm/svm/svm.c
View File

@ -115,13 +115,6 @@ static const struct svm_direct_access_msrs {
{ .index = MSR_INVALID, .always = false },
};
/* enable NPT for AMD64 and X86 with PAE */
#if defined(CONFIG_X86_64) || defined(CONFIG_X86_PAE)
bool npt_enabled = true;
#else
bool npt_enabled;
#endif
/*
* These 2 parameters are used to config the controls for Pause-Loop Exiting:
* pause_filter_count: On processors that support Pause filtering(indicated
@ -170,9 +163,12 @@ module_param(pause_filter_count_shrink, ushort, 0444);
static unsigned short pause_filter_count_max = KVM_SVM_DEFAULT_PLE_WINDOW_MAX;
module_param(pause_filter_count_max, ushort, 0444);
/* allow nested paging (virtualized MMU) for all guests */
static int npt = true;
module_param(npt, int, S_IRUGO);
/*
* Use nested page tables by default. Note, NPT may get forced off by
* svm_hardware_setup() if it's unsupported by hardware or the host kernel.
*/
bool npt_enabled = true;
module_param_named(npt, npt_enabled, bool, 0444);
/* allow nested virtualization in KVM/SVM */
static int nested = true;
@ -988,10 +984,15 @@ static __init int svm_hardware_setup(void)
goto err;
}
if (!boot_cpu_has(X86_FEATURE_NPT))
/*
* KVM's MMU doesn't support using 2-level paging for itself, and thus
* NPT isn't supported if the host is using 2-level paging since host
* CR4 is unchanged on VMRUN.
*/
if (!IS_ENABLED(CONFIG_X86_64) && !IS_ENABLED(CONFIG_X86_PAE))
npt_enabled = false;
if (npt_enabled && !npt)
if (!boot_cpu_has(X86_FEATURE_NPT))
npt_enabled = false;
kvm_configure_mmu(npt_enabled, get_max_npt_level(), PG_LEVEL_1G);