| Message ID | 1416302078-6324-1-git-send-email-tiejun.chen@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 18/11/2014 10:14, Tiejun Chen wrote: > Actually MMIO_MAX_GEN is same as MMIO_GEN_MASK, and > especially in all cases we already AND this so its > also unnecessary to generate such a WARN_ON(). > > Signed-off-by: Tiejun Chen <tiejun.chen@intel.com> Good idea, but I actually prefer keeping MMIO_GEN_MASK since it is often used together with an "&". Then, the WARN_ON is better written as - WARN_ON(gen > MMIO_MAX_GEN); + WARN_ON(gen & ~MMIO_GEN_MASK); Paolo > --- > arch/x86/kvm/mmu.c | 5 +---- > 1 file changed, 1 insertion(+), 4 deletions(-) > > diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c > index ac1c4de..7712345 100644 > --- a/arch/x86/kvm/mmu.c > +++ b/arch/x86/kvm/mmu.c > @@ -213,15 +213,12 @@ EXPORT_SYMBOL_GPL(kvm_mmu_set_mmio_spte_mask); > #define MMIO_GEN_SHIFT 20 > #define MMIO_GEN_LOW_SHIFT 10 > #define MMIO_GEN_LOW_MASK ((1 << MMIO_GEN_LOW_SHIFT) - 2) > -#define MMIO_GEN_MASK ((1 << MMIO_GEN_SHIFT) - 1) > #define MMIO_MAX_GEN ((1 << MMIO_GEN_SHIFT) - 1) > > static u64 generation_mmio_spte_mask(unsigned int gen) > { > u64 mask; > > - WARN_ON(gen > MMIO_MAX_GEN); > - > mask = (gen & MMIO_GEN_LOW_MASK) << MMIO_SPTE_GEN_LOW_SHIFT; > mask |= ((u64)gen >> MMIO_GEN_LOW_SHIFT) << MMIO_SPTE_GEN_HIGH_SHIFT; > return mask; > @@ -240,7 +237,7 @@ static unsigned int get_mmio_spte_generation(u64 spte) > > static unsigned int kvm_current_mmio_generation(struct kvm *kvm) > { > - return kvm_memslots(kvm)->generation & MMIO_GEN_MASK; > + return kvm_memslots(kvm)->generation & MMIO_MAX_GEN; > } > > static void mark_mmio_spte(struct kvm *kvm, u64 *sptep, u64 gfn, > -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index ac1c4de..7712345 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -213,15 +213,12 @@ EXPORT_SYMBOL_GPL(kvm_mmu_set_mmio_spte_mask); #define MMIO_GEN_SHIFT 20 #define MMIO_GEN_LOW_SHIFT 10 #define MMIO_GEN_LOW_MASK ((1 << MMIO_GEN_LOW_SHIFT) - 2) -#define MMIO_GEN_MASK ((1 << MMIO_GEN_SHIFT) - 1) #define MMIO_MAX_GEN ((1 << MMIO_GEN_SHIFT) - 1) static u64 generation_mmio_spte_mask(unsigned int gen) { u64 mask; - WARN_ON(gen > MMIO_MAX_GEN); - mask = (gen & MMIO_GEN_LOW_MASK) << MMIO_SPTE_GEN_LOW_SHIFT; mask |= ((u64)gen >> MMIO_GEN_LOW_SHIFT) << MMIO_SPTE_GEN_HIGH_SHIFT; return mask; @@ -240,7 +237,7 @@ static unsigned int get_mmio_spte_generation(u64 spte) static unsigned int kvm_current_mmio_generation(struct kvm *kvm) { - return kvm_memslots(kvm)->generation & MMIO_GEN_MASK; + return kvm_memslots(kvm)->generation & MMIO_MAX_GEN; } static void mark_mmio_spte(struct kvm *kvm, u64 *sptep, u64 gfn,
Actually MMIO_MAX_GEN is same as MMIO_GEN_MASK, and especially in all cases we already AND this so its also unnecessary to generate such a WARN_ON(). Signed-off-by: Tiejun Chen <tiejun.chen@intel.com> --- arch/x86/kvm/mmu.c | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-)