| Message ID | 5014F0E1.4010909@linux.vnet.ibm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Sun, Jul 29, 2012 at 04:14:25PM +0800, Xiao Guangrong wrote: > Then, remove get_bad_pfn > > Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> > --- > include/linux/kvm_host.h | 1 + > virt/kvm/kvm_main.c | 7 +------ > 2 files changed, 2 insertions(+), 6 deletions(-) > > diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h > index 4de56cd..b02203f 100644 > --- a/include/linux/kvm_host.h > +++ b/include/linux/kvm_host.h > @@ -50,6 +50,7 @@ > > #define kvm_fault_pfn (-EFAULT) > #define kvm_hwpoison_pfn (-EHWPOISON) > +#define kvm_bad_pfn (-ENOENT) Remind me what is the guarantee that -Exxx does not clash with a valid pfn number? -- 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
On Thu, Aug 02, 2012 at 10:15:27AM -0300, Marcelo Tosatti wrote: > Remind me what is the guarantee that -Exxx does not clash with > a valid pfn number? A pfn number is an address >> PAGE_SHIFT, so it will have the top 12 (at least) bits clear, whereas -Exxx will have the top bit set. Paul. -- 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
Marcelo, Paul, Thanks for your review! On 08/03/2012 08:01 AM, Paul Mackerras wrote: > On Thu, Aug 02, 2012 at 10:15:27AM -0300, Marcelo Tosatti wrote: > >> Remind me what is the guarantee that -Exxx does not clash with >> a valid pfn number? > > A pfn number is an address >> PAGE_SHIFT, so it will have the top 12 > (at least) bits clear, whereas -Exxx will have the top bit set. > Yes. As this way is hard to understand and it will break huge memory support on PAE 32bit cpu, i have used a new way in the v2: http://marc.info/?l=linux-kernel&m=134398012027025&w=2 Please review the new version. -- 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/include/linux/kvm_host.h b/include/linux/kvm_host.h index 4de56cd..b02203f 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -50,6 +50,7 @@ #define kvm_fault_pfn (-EFAULT) #define kvm_hwpoison_pfn (-EHWPOISON) +#define kvm_bad_pfn (-ENOENT) /* * vcpu->requests bit members diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 390a03d..da16191 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -943,11 +943,6 @@ int is_error_pfn(pfn_t pfn) } EXPORT_SYMBOL_GPL(is_error_pfn); -static pfn_t get_bad_pfn(void) -{ - return -ENOENT; -} - int is_noslot_pfn(pfn_t pfn) { return pfn == -ENOENT; @@ -1152,7 +1147,7 @@ static pfn_t __gfn_to_pfn(struct kvm *kvm, gfn_t gfn, bool atomic, bool *async, addr = gfn_to_hva(kvm, gfn); if (kvm_is_error_hva(addr)) - return get_bad_pfn(); + return kvm_bad_pfn; return hva_to_pfn(addr, atomic, async, write_fault, writable); }
Then, remove get_bad_pfn Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> --- include/linux/kvm_host.h | 1 + virt/kvm/kvm_main.c | 7 +------ 2 files changed, 2 insertions(+), 6 deletions(-)