Hi Andrew,
On 21/12/2018 14:14, Andrew Cooper wrote:
On 20/12/2018 19:23, Julien Grall wrote:
diff --git a/xen/arch/x86/domain.c b/xen/arch/x86/domain.c
index 32dc4253ff..b462a8513b 100644
--- a/xen/arch/x86/domain.c
+++ b/xen/arch/x86/domain.c
@@ -827,7 +827,7 @@ int arch_set_info_guest(
unsigned long flags;
bool compat;
#ifdef CONFIG_PV
- unsigned long cr3_gfn;
+ gfn_t cr3_gfn;
I've sent an alternative patch which this patch should be rebased over,
at which point all modifications to arch_set_info_guest() should
hopefully disappear.
The rest of the series should be merged by end of today (Code freeze for Xen
Arm). So I will resend this patch separately after my holidays.
diff --git a/xen/arch/x86/hvm/domain.c b/xen/arch/x86/hvm/domain.c
index 5d5a746a25..73d2da8441 100644
--- a/xen/arch/x86/hvm/domain.c
+++ b/xen/arch/x86/hvm/domain.c
@@ -297,7 +297,7 @@ int arch_set_info_hvm_guest(struct vcpu *v, const
vcpu_hvm_context_t *ctx)
{
/* Shadow-mode CR3 change. Check PDBR and update refcounts. */
struct page_info *page = get_page_from_gfn(v->domain,
- v->arch.hvm.guest_cr[3] >> PAGE_SHIFT,
+ gaddr_to_gfn(v->arch.hvm.guest_cr[3]),
NULL, P2M_ALLOC);
Can you re-indent while modifying this please?
Sure.
diff --git a/xen/arch/x86/hvm/viridian/time.c b/xen/arch/x86/hvm/viridian/time.c
index 840a82b457..a718434456 100644
--- a/xen/arch/x86/hvm/viridian/time.c
+++ b/xen/arch/x86/hvm/viridian/time.c
@@ -38,16 +38,16 @@ static void dump_reference_tsc(const struct domain *d)
static void update_reference_tsc(struct domain *d, bool initialize)
{
- unsigned long gmfn = d->arch.hvm.viridian.reference_tsc.fields.pfn;
- struct page_info *page = get_page_from_gfn(d, gmfn, NULL, P2M_ALLOC);
+ gfn_t gfn = _gfn(d->arch.hvm.viridian.reference_tsc.fields.pfn);
+ struct page_info *page = get_page_from_gfn(d, gfn, NULL, P2M_ALLOC);
HV_REFERENCE_TSC_PAGE *p;
if ( !page || !get_page_type(page, PGT_writable_page) )
{
if ( page )
put_page(page);
- gdprintk(XENLOG_WARNING, "Bad GMFN %#"PRI_gfn" (MFN %#"PRI_mfn")\n",
- gmfn, mfn_x(page ? page_to_mfn(page) : INVALID_MFN));
+ gdprintk(XENLOG_WARNING, "Bad GFN %#"PRI_gfn" (MFN %#"PRI_mfn")\n",
The canonical format for gfns and mfns are just %"PRI_*, without the #
Do you mind fixing this seeing as you're changing the string anyway?
Sure.
diff --git a/xen/include/asm-x86/p2m.h b/xen/include/asm-x86/p2m.h
index 3304921991..1efbc071c5 100644
--- a/xen/include/asm-x86/p2m.h
+++ b/xen/include/asm-x86/p2m.h
@@ -491,18 +491,21 @@ struct page_info *p2m_get_page_from_gfn(struct p2m_domain
*p2m, gfn_t gfn,
p2m_query_t q);
static inline struct page_info *get_page_from_gfn(
- struct domain *d, unsigned long gfn, p2m_type_t *t, p2m_query_t q)
+ struct domain *d, gfn_t gfn, p2m_type_t *t, p2m_query_t q)
{
struct page_info *page;
+ mfn_t mfn;
if ( paging_mode_translate(d) )
- return p2m_get_page_from_gfn(p2m_get_hostp2m(d), _gfn(gfn), t, NULL,
q);
+ return p2m_get_page_from_gfn(p2m_get_hostp2m(d), gfn, t, NULL, q);
/* Non-translated guests see 1-1 RAM / MMIO mappings everywhere */
if ( t )
*t = likely(d != dom_io) ? p2m_ram_rw : p2m_mmio_direct;
- page = mfn_to_page(_mfn(gfn));
- return mfn_valid(_mfn(gfn)) && get_page(page, d) ? page : NULL;
+
+ mfn = _mfn(gfn_x(gfn));
+ page = mfn_to_page(mfn);
+ return mfn_valid(mfn) && get_page(page, d) ? page : NULL;
This unfortunately propagates some bad behaviour, because it is not safe
to use mfn_to_page(mfn); before mfn_valid(mfn) succeeds. (In practice
it works because mfn_to_page() is just pointer arithmetic.)
Pleas can you express this as:
return (mfn_valid(mfn) &&
(page = mfn_to_page(mfn), get_page(page, d))) ? page : NULL;
which at least gets the order of operations in the correct order from
C's point of view.
Alternatively, and perhaps easier to follow:
if ( !mfn_valid(mfn) )
return NULL;
page = mfn_to_page(mfn);
return get_page(page, d) ? page : NULL;
I am happy to fix that. However, shouldn't this be handled in a separate patch?
After all, the code is not worst than it currently is.
Cheers,
~Andrew
--
Julien Grall
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