On Sat, 2007-09-22 at 00:32 +0200, Andi Kleen wrote:
> Also allow to set svm lock.
Please use two separate patches. The detection and cpuinfo display is
not related to set svm lock.
> TBD double check, documentation, i386 support
Yes, documentation would be useful. See below.
> Signed-off-by: Andi Kleen <[email protected]>
>
> ---
> arch/x86_64/kernel/setup.c | 25 +++++++++++++++++++++++--
> include/asm-i386/cpufeature.h | 1 +
> include/asm-i386/msr-index.h | 3 +++
> 3 files changed, 27 insertions(+), 2 deletions(-)
>
> Index: linux/arch/x86_64/kernel/setup.c
> ===================================================================
> --- linux.orig/arch/x86_64/kernel/setup.c
> +++ linux/arch/x86_64/kernel/setup.c
> @@ -565,7 +565,7 @@ static void __cpuinit early_init_amd(str
>
> static void __cpuinit init_amd(struct cpuinfo_x86 *c)
> {
> - unsigned level;
> + unsigned level, flags, dummy;
>
> #ifdef CONFIG_SMP
> unsigned long value;
> @@ -634,7 +634,28 @@ static void __cpuinit init_amd(struct cp
> /* Family 10 doesn't support C states in MWAIT so don't use it */
> if (c->x86 == 0x10 && !force_mwait)
> clear_bit(X86_FEATURE_MWAIT, &c->x86_capability);
> +
> + if (c->x86 >= 0xf && c->x86 <= 0x11 &&
> + !rdmsr_safe(MSR_VM_CR, &flags, &dummy) &&
> + (flags & 0x18))
> + set_bit(X86_FEATURE_VIRT_DISABLED, &c->x86_capability);
Why the check for 0x18 ???? And please can we use understandable
constants for this.
bit 3 (SVM_LOCK) controls only the writeability of bit 4 (SVME_DISABLE),
which controls whether SVM is allowed to be enabled or not.
bit 3 bit 4
0 0 SVM can be enabled in EFER, SVME_DISABLE is writeable
1 0 SVM can be enabled in EFER, SVME_DISABLE is not writeable
0 1 SVM can not be enabled in EFER, SVME_DISABLE is writeable
1 1 SVM can not be enabled in EFER, SVME_DISABLE is not writeable
So SVM is disabled, when bit 4 is set.
> +}
> +
> +static int enable_svm_lock(char *s)
> +{
> + if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD &&
> + boot_cpu_data.x86 >= 0xf && boot_cpu_data.x86 <= 0x11) {
> + unsigned a,b;
> + if (rdmsr_safe(MSR_VM_CR, &a, &b))
> + return 0;
> + a |= (1 << 3); /* set SVM lock */
SVM_LOCK is read only according to data sheet. You can set bit 4
(SVME_DISABLE) to prevent KVM or what else using that feature.
tglx
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
[Index of Archives]
[Kernel Newbies]
[Netfilter]
[Bugtraq]
[Photo]
[Stuff]
[Gimp]
[Yosemite News]
[MIPS Linux]
[ARM Linux]
[Linux Security]
[Linux RAID]
[Video 4 Linux]
[Linux for the blind]
[Linux Resources]
