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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH v2 3/4] x86/hvm: Break out __hvm_copy()'s translation logic
From: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
It will be reused by later changes.
Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
Signed-off-by: Alexandru Isaila <aisaila@xxxxxxxxxxxxxxx>
---
CC: Jan Beulich <JBeulich@xxxxxxxx>
Changes since V1:
- Changed param name
- Added ASSERT
---
xen/arch/x86/hvm/hvm.c | 144 +++++++++++++++++++++++---------------
xen/include/asm-x86/hvm/support.h | 12 ++++
2 files changed, 98 insertions(+), 58 deletions(-)
diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c
index 488acbf..a60149a 100644
--- a/xen/arch/x86/hvm/hvm.c
+++ b/xen/arch/x86/hvm/hvm.c
@@ -3069,6 +3069,83 @@ void hvm_task_switch(
hvm_unmap_entry(nptss_desc);
}
+enum hvm_translation_result hvm_translate_get_page(
+ struct vcpu *v, unsigned long addr, bool linear, uint32_t pfec,
+ pagefault_info_t *pfinfo, struct page_info **page_p,
+ gfn_t *gfn_p, p2m_type_t *p2mt_p)
+{
+ struct page_info *page;
+ p2m_type_t p2mt;
+ gfn_t gfn;
+
+ if ( linear )
+ {
+ gfn = _gfn(paging_gva_to_gfn(v, addr, &pfec));
+
+ if ( gfn_eq(gfn, INVALID_GFN) )
+ {
+ if ( pfec & PFEC_page_paged )
+ return HVMTRANS_gfn_paged_out;
+
+ if ( pfec & PFEC_page_shared )
+ return HVMTRANS_gfn_shared;
+
+ if ( pfinfo )
+ {
+ pfinfo->linear = addr;
+ pfinfo->ec = pfec & ~PFEC_implicit;
+ }
+
+ return HVMTRANS_bad_linear_to_gfn;
+ }
+ }
+ else
+ {
+ gfn = _gfn(addr >> PAGE_SHIFT);
+ ASSERT(!pfinfo);
+ }
+
+ /*
+ * No need to do the P2M lookup for internally handled MMIO, benefiting
+ * - 32-bit WinXP (& older Windows) on AMD CPUs for LAPIC accesses,
+ * - newer Windows (like Server 2012) for HPET accesses.
+ */
+ if ( v == current
+ && !nestedhvm_vcpu_in_guestmode(v)
+ && hvm_mmio_internal(gfn_x(gfn) << PAGE_SHIFT) )
+ return HVMTRANS_bad_gfn_to_mfn;
+
+ page = get_page_from_gfn(v->domain, gfn_x(gfn), &p2mt, P2M_UNSHARE);
+
+ if ( !page )
+ return HVMTRANS_bad_gfn_to_mfn;
+
+ if ( p2m_is_paging(p2mt) )
+ {
+ put_page(page);
+ p2m_mem_paging_populate(v->domain, gfn_x(gfn));
+ return HVMTRANS_gfn_paged_out;
+ }
+ if ( p2m_is_shared(p2mt) )
+ {
+ put_page(page);
+ return HVMTRANS_gfn_shared;
+ }
+ if ( p2m_is_grant(p2mt) )
+ {
+ put_page(page);
+ return HVMTRANS_unhandleable;
+ }
+
+ *page_p = page;
+ if ( gfn_p )
+ *gfn_p = gfn;
+ if ( p2mt_p )
+ *p2mt_p = p2mt;
+
+ return HVMTRANS_okay;
+}
+
#define HVMCOPY_from_guest (0u<<0)
#define HVMCOPY_to_guest (1u<<0)
#define HVMCOPY_phys (0u<<2)
@@ -3077,7 +3154,7 @@ static enum hvm_translation_result __hvm_copy(
void *buf, paddr_t addr, int size, struct vcpu *v, unsigned int flags,
uint32_t pfec, pagefault_info_t *pfinfo)
{
- unsigned long gfn;
+ gfn_t gfn;
struct page_info *page;
p2m_type_t p2mt;
char *p;
@@ -3103,65 +3180,15 @@ static enum hvm_translation_result __hvm_copy(
while ( todo > 0 )
{
+ enum hvm_translation_result res;
paddr_t gpa = addr & ~PAGE_MASK;
count = min_t(int, PAGE_SIZE - gpa, todo);
- if ( flags & HVMCOPY_linear )
- {
- gfn = paging_gva_to_gfn(v, addr, &pfec);
- if ( gfn == gfn_x(INVALID_GFN) )
- {
- if ( pfec & PFEC_page_paged )
- return HVMTRANS_gfn_paged_out;
- if ( pfec & PFEC_page_shared )
- return HVMTRANS_gfn_shared;
- if ( pfinfo )
- {
- pfinfo->linear = addr;
- pfinfo->ec = pfec & ~PFEC_implicit;
- }
- return HVMTRANS_bad_linear_to_gfn;
- }
- gpa |= (paddr_t)gfn << PAGE_SHIFT;
- }
- else
- {
- gfn = addr >> PAGE_SHIFT;
- gpa = addr;
- }
-
- /*
- * No need to do the P2M lookup for internally handled MMIO, benefiting
- * - 32-bit WinXP (& older Windows) on AMD CPUs for LAPIC accesses,
- * - newer Windows (like Server 2012) for HPET accesses.
- */
- if ( v == current
- && !nestedhvm_vcpu_in_guestmode(v)
- && hvm_mmio_internal(gpa) )
- return HVMTRANS_bad_gfn_to_mfn;
-
- page = get_page_from_gfn(v->domain, gfn, &p2mt, P2M_UNSHARE);
-
- if ( !page )
- return HVMTRANS_bad_gfn_to_mfn;
-
- if ( p2m_is_paging(p2mt) )
- {
- put_page(page);
- p2m_mem_paging_populate(v->domain, gfn);
- return HVMTRANS_gfn_paged_out;
- }
- if ( p2m_is_shared(p2mt) )
- {
- put_page(page);
- return HVMTRANS_gfn_shared;
- }
- if ( p2m_is_grant(p2mt) )
- {
- put_page(page);
- return HVMTRANS_unhandleable;
- }
+ res = hvm_translate_get_page(v, addr, flags & HVMCOPY_linear,
+ pfec, pfinfo, &page, &gfn, &p2mt);
+ if ( res != HVMTRANS_okay )
+ return res;
p = (char *)__map_domain_page(page) + (addr & ~PAGE_MASK);
@@ -3170,10 +3197,11 @@ static enum hvm_translation_result __hvm_copy(
if ( p2m_is_discard_write(p2mt) )
{
static unsigned long lastpage;
- if ( xchg(&lastpage, gfn) != gfn )
+
+ if ( xchg(&lastpage, gfn_x(gfn)) != gfn_x(gfn) )
dprintk(XENLOG_G_DEBUG,
"%pv attempted write to read-only gfn %#lx
(mfn=%#lx)\n",
- v, gfn, page_to_mfn(page));
+ v, gfn_x(gfn), page_to_mfn(page));
}
else
{
diff --git a/xen/include/asm-x86/hvm/support.h
b/xen/include/asm-x86/hvm/support.h
index e3b035d..d784fc1 100644
--- a/xen/include/asm-x86/hvm/support.h
+++ b/xen/include/asm-x86/hvm/support.h
@@ -24,6 +24,7 @@
#include <xen/sched.h>
#include <asm/hvm/save.h>
#include <asm/processor.h>
+#include <asm/p2m.h>
#ifndef NDEBUG
#define DBG_LEVEL_0 (1 << 0)
@@ -103,6 +104,17 @@ enum hvm_translation_result hvm_fetch_from_guest_linear(
void *buf, unsigned long addr, int size, uint32_t pfec,
pagefault_info_t *pfinfo);
+/*
+ * Get a reference on the page under an HVM physical or linear address. If
+ * linear, a pagewalk is performed using pfec (fault details optionally in
+ * pfinfo).
+ * On success, returns HVMTRANS_okay with a reference taken on **_page.
+ */
+enum hvm_translation_result hvm_translate_get_page(
+ struct vcpu *v, unsigned long addr, bool linear, uint32_t pfec,
+ pagefault_info_t *pfinfo, struct page_info **page_p,
+ gfn_t *gfn_p, p2m_type_t *p2mt_p);
+
#define HVM_HCALL_completed 0 /* hypercall completed - no further action */
#define HVM_HCALL_preempted 1 /* hypercall preempted - re-execute VMCALL */
int hvm_hypercall(struct cpu_user_regs *regs);
--
2.7.4
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