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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [PATCH v11 1/3] x86/tlb: introduce a flush HVM ASIDs flag
Introduce a specific flag to request a HVM guest linear TLB flush,
which is an ASID/VPID tickle that forces a guest linear to guest
physical TLB flush for all HVM guests.
This was previously unconditionally done in each pre_flush call, but
that's not required: HVM guests not using shadow don't require linear
TLB flushes as Xen doesn't modify the pages tables the guest runs on
in that case (ie: when using HAP). Note that shadow paging code
already takes care of issuing the necessary flushes when the shadow
page tables are modified.
In order to keep the previous behavior modify all shadow code TLB
flushes to also flush the guest linear to physical TLB if the guest is
HVM. I haven't looked at each specific shadow code TLB flush in order
to figure out whether it actually requires a guest TLB flush or not,
so there might be room for improvement in that regard.
Also perform ASID/VPID flushes when modifying the p2m tables as it's a
requirement for AMD hardware. Finally keep the flush in
switch_cr3_cr4, as it's not clear whether code could rely on
switch_cr3_cr4 also performing a guest linear TLB flush. A following
patch can remove the ASID/VPID tickle from switch_cr3_cr4 if found to
not be necessary.
Signed-off-by: Roger Pau Monné <roger.pau@xxxxxxxxxx>
---
Changes since v10:
- Reword commit message.
- Split flags generation in guest_flush_tlb_mask to a separate
helper.
- Move sh_flush_local into multi.c and make it use
guest_flush_tlb_flags.
- Flush ASID always when running HVM domains in shadow mode.
Changes since v9:
- Introduce and use guest_flush_tlb_mask and sh_flush_local.
- Add a local domain variable to p2m_pt_change_entry_type_global.
Changes since v8:
- Don't flush host TLB on HAP changes.
- Introduce a helper for shadow changes that only flushes ASIDs/VPIDs
when the guest is HVM.
- Introduce a helper for HAP that only flushes ASIDs/VPIDs.
Changes since v7:
- Do not perform an ASID flush in filtered_flush_tlb_mask: the
requested flush is related to the page need_tlbflush field and not
to p2m changes (applies to both callers).
Changes since v6:
- Add ASID/VPID flushes when modifying the p2m.
- Keep the ASID/VPID flush in switch_cr3_cr4.
Changes since v5:
- Rename FLUSH_GUESTS_TLB to FLUSH_HVM_ASID_CORE.
- Clarify commit message.
- Define FLUSH_HVM_ASID_CORE to 0 when !CONFIG_HVM.
---
xen/arch/x86/flushtlb.c | 23 +++++++++++++++++++++--
xen/arch/x86/mm/hap/hap.c | 8 ++++----
xen/arch/x86/mm/hap/nested_hap.c | 2 +-
xen/arch/x86/mm/p2m-pt.c | 5 +++--
xen/arch/x86/mm/paging.c | 2 +-
xen/arch/x86/mm/shadow/common.c | 18 +++++++++---------
xen/arch/x86/mm/shadow/hvm.c | 2 +-
xen/arch/x86/mm/shadow/multi.c | 22 ++++++++++++++--------
xen/include/asm-x86/flushtlb.h | 9 +++++++++
9 files changed, 63 insertions(+), 28 deletions(-)
diff --git a/xen/arch/x86/flushtlb.c b/xen/arch/x86/flushtlb.c
index 03f92c23dc..0c40b5d273 100644
--- a/xen/arch/x86/flushtlb.c
+++ b/xen/arch/x86/flushtlb.c
@@ -7,6 +7,7 @@
* Copyright (c) 2003-2006, K A Fraser
*/
+#include <xen/paging.h>
#include <xen/sched.h>
#include <xen/smp.h>
#include <xen/softirq.h>
@@ -59,8 +60,6 @@ static u32 pre_flush(void)
raise_softirq(NEW_TLBFLUSH_CLOCK_PERIOD_SOFTIRQ);
skip_clocktick:
- hvm_flush_guest_tlbs();
-
return t2;
}
@@ -118,6 +117,7 @@ void switch_cr3_cr4(unsigned long cr3, unsigned long cr4)
local_irq_save(flags);
t = pre_flush();
+ hvm_flush_guest_tlbs();
old_cr4 = read_cr4();
ASSERT(!(old_cr4 & X86_CR4_PCIDE) || !(old_cr4 & X86_CR4_PGE));
@@ -221,6 +221,9 @@ unsigned int flush_area_local(const void *va, unsigned int
flags)
do_tlb_flush();
}
+ if ( flags & FLUSH_HVM_ASID_CORE )
+ hvm_flush_guest_tlbs();
+
if ( flags & FLUSH_CACHE )
{
const struct cpuinfo_x86 *c = ¤t_cpu_data;
@@ -254,3 +257,19 @@ unsigned int flush_area_local(const void *va, unsigned int
flags)
return flags;
}
+
+unsigned int guest_flush_tlb_flags(const struct domain *d)
+{
+ bool shadow = paging_mode_shadow(d);
+ bool asid = is_hvm_domain(d) && (cpu_has_svm || shadow);
+
+ return (shadow ? FLUSH_TLB : 0) | (asid ? FLUSH_HVM_ASID_CORE : 0);
+}
+
+void guest_flush_tlb_mask(const struct domain *d, const cpumask_t *mask)
+{
+ unsigned int flags = guest_flush_tlb_flags(d);
+
+ if ( flags )
+ flush_mask(mask, flags);
+}
diff --git a/xen/arch/x86/mm/hap/hap.c b/xen/arch/x86/mm/hap/hap.c
index 11829e7aad..580d1c2164 100644
--- a/xen/arch/x86/mm/hap/hap.c
+++ b/xen/arch/x86/mm/hap/hap.c
@@ -118,7 +118,7 @@ int hap_track_dirty_vram(struct domain *d,
p2m_change_type_range(d, begin_pfn, begin_pfn + nr,
p2m_ram_rw, p2m_ram_logdirty);
- flush_tlb_mask(d->dirty_cpumask);
+ guest_flush_tlb_mask(d, d->dirty_cpumask);
memset(dirty_bitmap, 0xff, size); /* consider all pages dirty */
}
@@ -205,7 +205,7 @@ static int hap_enable_log_dirty(struct domain *d, bool_t
log_global)
* to be read-only, or via hardware-assisted log-dirty.
*/
p2m_change_entry_type_global(d, p2m_ram_rw, p2m_ram_logdirty);
- flush_tlb_mask(d->dirty_cpumask);
+ guest_flush_tlb_mask(d, d->dirty_cpumask);
}
return 0;
}
@@ -234,7 +234,7 @@ static void hap_clean_dirty_bitmap(struct domain *d)
* be read-only, or via hardware-assisted log-dirty.
*/
p2m_change_entry_type_global(d, p2m_ram_rw, p2m_ram_logdirty);
- flush_tlb_mask(d->dirty_cpumask);
+ guest_flush_tlb_mask(d, d->dirty_cpumask);
}
/************************************************/
@@ -812,7 +812,7 @@ hap_write_p2m_entry(struct p2m_domain *p2m, unsigned long
gfn, l1_pgentry_t *p,
safe_write_pte(p, new);
if ( old_flags & _PAGE_PRESENT )
- flush_tlb_mask(d->dirty_cpumask);
+ guest_flush_tlb_mask(d, d->dirty_cpumask);
paging_unlock(d);
diff --git a/xen/arch/x86/mm/hap/nested_hap.c b/xen/arch/x86/mm/hap/nested_hap.c
index abe5958a52..f92ddc5206 100644
--- a/xen/arch/x86/mm/hap/nested_hap.c
+++ b/xen/arch/x86/mm/hap/nested_hap.c
@@ -84,7 +84,7 @@ nestedp2m_write_p2m_entry(struct p2m_domain *p2m, unsigned
long gfn,
safe_write_pte(p, new);
if (old_flags & _PAGE_PRESENT)
- flush_tlb_mask(p2m->dirty_cpumask);
+ guest_flush_tlb_mask(d, p2m->dirty_cpumask);
paging_unlock(d);
diff --git a/xen/arch/x86/mm/p2m-pt.c b/xen/arch/x86/mm/p2m-pt.c
index eb66077496..5c0501794e 100644
--- a/xen/arch/x86/mm/p2m-pt.c
+++ b/xen/arch/x86/mm/p2m-pt.c
@@ -866,11 +866,12 @@ static void p2m_pt_change_entry_type_global(struct
p2m_domain *p2m,
l1_pgentry_t *tab;
unsigned long gfn = 0;
unsigned int i, changed;
+ const struct domain *d = p2m->domain;
if ( pagetable_get_pfn(p2m_get_pagetable(p2m)) == 0 )
return;
- ASSERT(hap_enabled(p2m->domain));
+ ASSERT(hap_enabled(d));
tab = map_domain_page(pagetable_get_mfn(p2m_get_pagetable(p2m)));
for ( changed = i = 0; i < (1 << PAGETABLE_ORDER); ++i )
@@ -896,7 +897,7 @@ static void p2m_pt_change_entry_type_global(struct
p2m_domain *p2m,
unmap_domain_page(tab);
if ( changed )
- flush_tlb_mask(p2m->domain->dirty_cpumask);
+ guest_flush_tlb_mask(d, d->dirty_cpumask);
}
static int p2m_pt_change_entry_type_range(struct p2m_domain *p2m,
diff --git a/xen/arch/x86/mm/paging.c b/xen/arch/x86/mm/paging.c
index f5ff5d67a0..7c265fb5f3 100644
--- a/xen/arch/x86/mm/paging.c
+++ b/xen/arch/x86/mm/paging.c
@@ -613,7 +613,7 @@ void paging_log_dirty_range(struct domain *d,
p2m_unlock(p2m);
- flush_tlb_mask(d->dirty_cpumask);
+ guest_flush_tlb_mask(d, d->dirty_cpumask);
}
/*
diff --git a/xen/arch/x86/mm/shadow/common.c b/xen/arch/x86/mm/shadow/common.c
index 3746dd6fb0..7ed8e7b71b 100644
--- a/xen/arch/x86/mm/shadow/common.c
+++ b/xen/arch/x86/mm/shadow/common.c
@@ -368,7 +368,7 @@ static int oos_remove_write_access(struct vcpu *v, mfn_t
gmfn,
}
if ( ftlb )
- flush_tlb_mask(d->dirty_cpumask);
+ guest_flush_tlb_mask(d, d->dirty_cpumask);
return 0;
}
@@ -946,7 +946,7 @@ static void _shadow_prealloc(struct domain *d, unsigned int
pages)
/* See if that freed up enough space */
if ( d->arch.paging.shadow.free_pages >= pages )
{
- flush_tlb_mask(d->dirty_cpumask);
+ guest_flush_tlb_mask(d, d->dirty_cpumask);
return;
}
}
@@ -1000,7 +1000,7 @@ static void shadow_blow_tables(struct domain *d)
pagetable_get_mfn(v->arch.shadow_table[i]), 0);
/* Make sure everyone sees the unshadowings */
- flush_tlb_mask(d->dirty_cpumask);
+ guest_flush_tlb_mask(d, d->dirty_cpumask);
}
void shadow_blow_tables_per_domain(struct domain *d)
@@ -1103,7 +1103,7 @@ mfn_t shadow_alloc(struct domain *d,
if ( unlikely(!cpumask_empty(&mask)) )
{
perfc_incr(shadow_alloc_tlbflush);
- flush_tlb_mask(&mask);
+ guest_flush_tlb_mask(d, &mask);
}
/* Now safe to clear the page for reuse */
clear_domain_page(page_to_mfn(sp));
@@ -2296,7 +2296,7 @@ void sh_remove_shadows(struct domain *d, mfn_t gmfn, int
fast, int all)
/* Need to flush TLBs now, so that linear maps are safe next time we
* take a fault. */
- flush_tlb_mask(d->dirty_cpumask);
+ guest_flush_tlb_mask(d, d->dirty_cpumask);
paging_unlock(d);
}
@@ -3013,7 +3013,7 @@ static void sh_unshadow_for_p2m_change(struct domain *d,
unsigned long gfn,
{
sh_remove_all_shadows_and_parents(d, mfn);
if ( sh_remove_all_mappings(d, mfn, _gfn(gfn)) )
- flush_tlb_mask(d->dirty_cpumask);
+ guest_flush_tlb_mask(d, d->dirty_cpumask);
}
}
@@ -3053,7 +3053,7 @@ static void sh_unshadow_for_p2m_change(struct domain *d,
unsigned long gfn,
}
omfn = mfn_add(omfn, 1);
}
- flush_tlb_mask(&flushmask);
+ guest_flush_tlb_mask(d, &flushmask);
if ( npte )
unmap_domain_page(npte);
@@ -3340,7 +3340,7 @@ int shadow_track_dirty_vram(struct domain *d,
}
}
if ( flush_tlb )
- flush_tlb_mask(d->dirty_cpumask);
+ guest_flush_tlb_mask(d, d->dirty_cpumask);
goto out;
out_sl1ma:
@@ -3410,7 +3410,7 @@ bool shadow_flush_tlb(bool (*flush_vcpu)(void *ctxt,
struct vcpu *v),
}
/* Flush TLBs on all CPUs with dirty vcpu state. */
- flush_tlb_mask(mask);
+ guest_flush_tlb_mask(d, mask);
/* Done. */
for_each_vcpu ( d, v )
diff --git a/xen/arch/x86/mm/shadow/hvm.c b/xen/arch/x86/mm/shadow/hvm.c
index 1e6024c71f..608360daec 100644
--- a/xen/arch/x86/mm/shadow/hvm.c
+++ b/xen/arch/x86/mm/shadow/hvm.c
@@ -591,7 +591,7 @@ static void validate_guest_pt_write(struct vcpu *v, mfn_t
gmfn,
if ( rc & SHADOW_SET_FLUSH )
/* Need to flush TLBs to pick up shadow PT changes */
- flush_tlb_mask(d->dirty_cpumask);
+ guest_flush_tlb_mask(d, d->dirty_cpumask);
if ( rc & SHADOW_SET_ERROR )
{
diff --git a/xen/arch/x86/mm/shadow/multi.c b/xen/arch/x86/mm/shadow/multi.c
index 5368adf474..7d16d1c1a9 100644
--- a/xen/arch/x86/mm/shadow/multi.c
+++ b/xen/arch/x86/mm/shadow/multi.c
@@ -85,6 +85,12 @@ const char *const fetch_type_names[] = {
};
#endif
+/* Helper to perform a local TLB flush. */
+static void sh_flush_local(const struct domain *d)
+{
+ flush_local(guest_flush_tlb_flags(d));
+}
+
/**************************************************************************/
/* Hash table mapping from guest pagetables to shadows
*
@@ -3075,7 +3081,7 @@ static int sh_page_fault(struct vcpu *v,
perfc_incr(shadow_rm_write_flush_tlb);
smp_wmb();
atomic_inc(&d->arch.paging.shadow.gtable_dirty_version);
- flush_tlb_mask(d->dirty_cpumask);
+ guest_flush_tlb_mask(d, d->dirty_cpumask);
}
#if (SHADOW_OPTIMIZATIONS & SHOPT_OUT_OF_SYNC)
@@ -3584,7 +3590,7 @@ static bool sh_invlpg(struct vcpu *v, unsigned long
linear)
if ( mfn_to_page(sl1mfn)->u.sh.type
== SH_type_fl1_shadow )
{
- flush_tlb_local();
+ sh_flush_local(v->domain);
return false;
}
@@ -3798,7 +3804,7 @@ sh_update_linear_entries(struct vcpu *v)
* linear pagetable to read a top-level shadow page table entry. But,
* without this change, it would fetch the wrong value due to a stale TLB.
*/
- flush_tlb_local();
+ sh_flush_local(d);
}
@@ -3998,7 +4004,7 @@ sh_update_cr3(struct vcpu *v, int do_locking, bool
noflush)
* (old) shadow linear maps in the writeable mapping heuristics. */
#if GUEST_PAGING_LEVELS == 2
if ( sh_remove_write_access(d, gmfn, 2, 0) != 0 )
- flush_tlb_mask(d->dirty_cpumask);
+ guest_flush_tlb_mask(d, d->dirty_cpumask);
sh_set_toplevel_shadow(v, 0, gmfn, SH_type_l2_shadow);
#elif GUEST_PAGING_LEVELS == 3
/* PAE guests have four shadow_table entries, based on the
@@ -4022,7 +4028,7 @@ sh_update_cr3(struct vcpu *v, int do_locking, bool
noflush)
}
}
if ( flush )
- flush_tlb_mask(d->dirty_cpumask);
+ guest_flush_tlb_mask(d, d->dirty_cpumask);
/* Now install the new shadows. */
for ( i = 0; i < 4; i++ )
{
@@ -4043,7 +4049,7 @@ sh_update_cr3(struct vcpu *v, int do_locking, bool
noflush)
}
#elif GUEST_PAGING_LEVELS == 4
if ( sh_remove_write_access(d, gmfn, 4, 0) != 0 )
- flush_tlb_mask(d->dirty_cpumask);
+ guest_flush_tlb_mask(d, d->dirty_cpumask);
sh_set_toplevel_shadow(v, 0, gmfn, SH_type_l4_shadow);
if ( !shadow_mode_external(d) && !is_pv_32bit_domain(d) )
{
@@ -4494,7 +4500,7 @@ static void sh_pagetable_dying(paddr_t gpa)
}
}
if ( flush )
- flush_tlb_mask(d->dirty_cpumask);
+ guest_flush_tlb_mask(d, d->dirty_cpumask);
/* Remember that we've seen the guest use this interface, so we
* can rely on it using it in future, instead of guessing at
@@ -4531,7 +4537,7 @@ static void sh_pagetable_dying(paddr_t gpa)
mfn_to_page(gmfn)->pagetable_dying = true;
shadow_unhook_mappings(d, smfn, 1/* user pages only */);
/* Now flush the TLB: we removed toplevel mappings. */
- flush_tlb_mask(d->dirty_cpumask);
+ guest_flush_tlb_mask(d, d->dirty_cpumask);
}
/* Remember that we've seen the guest use this interface, so we
diff --git a/xen/include/asm-x86/flushtlb.h b/xen/include/asm-x86/flushtlb.h
index 2cfe4e6e97..798049b6ad 100644
--- a/xen/include/asm-x86/flushtlb.h
+++ b/xen/include/asm-x86/flushtlb.h
@@ -105,6 +105,12 @@ void switch_cr3_cr4(unsigned long cr3, unsigned long cr4);
#define FLUSH_VCPU_STATE 0x1000
/* Flush the per-cpu root page table */
#define FLUSH_ROOT_PGTBL 0x2000
+#if CONFIG_HVM
+ /* Flush all HVM guests linear TLB (using ASID/VPID) */
+#define FLUSH_HVM_ASID_CORE 0x4000
+#else
+#define FLUSH_HVM_ASID_CORE 0
+#endif
/* Flush local TLBs/caches. */
unsigned int flush_area_local(const void *va, unsigned int flags);
@@ -159,4 +165,7 @@ static inline int clean_dcache_va_range(const void *p,
unsigned long size)
return clean_and_invalidate_dcache_va_range(p, size);
}
+unsigned int guest_flush_tlb_flags(const struct domain *d);
+void guest_flush_tlb_mask(const struct domain *d, const cpumask_t *mask);
+
#endif /* __FLUSHTLB_H__ */
--
2.26.0
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