| Message ID | 1469031064-23344-7-git-send-email-julien.grall@arm.com |
|---|---|
| State | New |
| Headers | show |
Hi Stefano, On 26/07/16 23:28, Stefano Stabellini wrote: > On Wed, 20 Jul 2016, Julien Grall wrote: >> @@ -411,7 +411,7 @@ static int p2m_create_table(struct domain *d, lpae_t *entry, >> if ( splitting ) >> { >> p2m_type_t t = entry->p2m.type; >> - unsigned long base_pfn = entry->p2m.base; >> + mfn_t mfn = _mfn(entry->p2m.base); >> int i; >> >> /* >> @@ -420,8 +420,9 @@ static int p2m_create_table(struct domain *d, lpae_t *entry, >> */ >> for ( i=0 ; i < LPAE_ENTRIES; i++ ) >> { >> - pte = mfn_to_p2m_entry(base_pfn + (i<<(level_shift-LPAE_SHIFT)), >> - MATTR_MEM, t, p2m->default_access); >> + pte = mfn_to_p2m_entry(mfn, MATTR_MEM, t, p2m->default_access); >> + >> + mfn = mfn_add(mfn, 1UL << (level_shift - LPAE_SHIFT)); > > Should we be incrementing mfn before calling mfn_to_p2m_entry? No. The base of the superpage is mfn, after splitting the first entry will be equal to the base, the second entry base + level_size... Regards,
Hi Stefano, On 27/07/2016 19:25, Stefano Stabellini wrote: > On Wed, 27 Jul 2016, Julien Grall wrote: >> Hi Stefano, >> >> On 26/07/16 23:28, Stefano Stabellini wrote: >>> On Wed, 20 Jul 2016, Julien Grall wrote: >>>> @@ -411,7 +411,7 @@ static int p2m_create_table(struct domain *d, lpae_t >>>> *entry, >>>> if ( splitting ) >>>> { >>>> p2m_type_t t = entry->p2m.type; >>>> - unsigned long base_pfn = entry->p2m.base; >>>> + mfn_t mfn = _mfn(entry->p2m.base); >>>> int i; >>>> >>>> /* >>>> @@ -420,8 +420,9 @@ static int p2m_create_table(struct domain *d, lpae_t >>>> *entry, >>>> */ >>>> for ( i=0 ; i < LPAE_ENTRIES; i++ ) >>>> { >>>> - pte = mfn_to_p2m_entry(base_pfn + >>>> (i<<(level_shift-LPAE_SHIFT)), >>>> - MATTR_MEM, t, p2m->default_access); >>>> + pte = mfn_to_p2m_entry(mfn, MATTR_MEM, t, >>>> p2m->default_access); >>>> + >>>> + mfn = mfn_add(mfn, 1UL << (level_shift - LPAE_SHIFT)); >>> >>> Should we be incrementing mfn before calling mfn_to_p2m_entry? >> >> No. The base of the superpage is mfn, after splitting the first entry will be >> equal to the base, the second entry base + level_size... > > I understand what the patch is doing now, I confused "1" with "i" :-) > The patch is OK. It might be more obvious as the following: > > > for ( i=0 ; i < LPAE_ENTRIES; i++ ) > { > pte = mfn_to_p2m_entry(mfn_add(mfn, (i<<(level_shift-LPAE_SHIFT))), > MATTR_MEM, t, p2m->default_access); > > > However it's just a matter of taste, so I'll let you choose the way you > prefer. I wanted to avoid shifting "i" at each loop (which should save an instruction). However, as it seems to be confusing, I will use your suggestion. > > Reviewed-by: Stefano Stabellini <sstabellini@kernel.org> Thank you! Cheers,
diff --git a/xen/arch/arm/p2m.c b/xen/arch/arm/p2m.c index d82349c..99be9be 100644 --- a/xen/arch/arm/p2m.c +++ b/xen/arch/arm/p2m.c @@ -324,7 +324,7 @@ static void p2m_set_permission(lpae_t *e, p2m_type_t t, p2m_access_t a) } } -static lpae_t mfn_to_p2m_entry(unsigned long mfn, unsigned int mattr, +static lpae_t mfn_to_p2m_entry(mfn_t mfn, unsigned int mattr, p2m_type_t t, p2m_access_t a) { /* @@ -358,9 +358,9 @@ static lpae_t mfn_to_p2m_entry(unsigned long mfn, unsigned int mattr, p2m_set_permission(&e, t, a); - ASSERT(!(pfn_to_paddr(mfn) & ~PADDR_MASK)); + ASSERT(!(pfn_to_paddr(mfn_x(mfn)) & ~PADDR_MASK)); - e.p2m.base = mfn; + e.p2m.base = mfn_x(mfn); return e; } @@ -411,7 +411,7 @@ static int p2m_create_table(struct domain *d, lpae_t *entry, if ( splitting ) { p2m_type_t t = entry->p2m.type; - unsigned long base_pfn = entry->p2m.base; + mfn_t mfn = _mfn(entry->p2m.base); int i; /* @@ -420,8 +420,9 @@ static int p2m_create_table(struct domain *d, lpae_t *entry, */ for ( i=0 ; i < LPAE_ENTRIES; i++ ) { - pte = mfn_to_p2m_entry(base_pfn + (i<<(level_shift-LPAE_SHIFT)), - MATTR_MEM, t, p2m->default_access); + pte = mfn_to_p2m_entry(mfn, MATTR_MEM, t, p2m->default_access); + + mfn = mfn_add(mfn, 1UL << (level_shift - LPAE_SHIFT)); /* * First and second level super pages set p2m.table = 0, but @@ -443,7 +444,7 @@ static int p2m_create_table(struct domain *d, lpae_t *entry, unmap_domain_page(p); - pte = mfn_to_p2m_entry(page_to_mfn(page), MATTR_MEM, p2m_invalid, + pte = mfn_to_p2m_entry(_mfn(page_to_mfn(page)), MATTR_MEM, p2m_invalid, p2m->default_access); p2m_write_pte(entry, pte, flush_cache); @@ -693,7 +694,7 @@ static int apply_one_level(struct domain *d, return rc; /* New mapping is superpage aligned, make it */ - pte = mfn_to_p2m_entry(*maddr >> PAGE_SHIFT, mattr, t, a); + pte = mfn_to_p2m_entry(_mfn(*maddr >> PAGE_SHIFT), mattr, t, a); if ( level < 3 ) pte.p2m.table = 0; /* Superpage entry */
Signed-off-by: Julien Grall <julien.grall@arm.com> --- xen/arch/arm/p2m.c | 17 +++++++++-------- 1 file changed, 9 insertions(+), 8 deletions(-)