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author | Olaf Hering <olaf@aepfle.de> | 2011-05-20 13:47:08 +0100 |
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committer | Olaf Hering <olaf@aepfle.de> | 2011-05-20 13:47:08 +0100 |
commit | ee48930b253ac67ea03b3d7313327f4cafbdc90f (patch) | |
tree | 17e7e3a891d6a0a1dafe84145900188caf788e40 | |
parent | c78bf518df0bb27b17d913783ffd1e0d5d2670af (diff) | |
download | xen-ee48930b253ac67ea03b3d7313327f4cafbdc90f.tar.gz xen-ee48930b253ac67ea03b3d7313327f4cafbdc90f.tar.bz2 xen-ee48930b253ac67ea03b3d7313327f4cafbdc90f.zip |
x86/mm: add HVMOP_get_mem_type hvmop
The balloon driver in the guest frees guest pages and marks them as
mmio. When the kernel crashes and the crash kernel attempts to read
the
oldmem via /proc/vmcore a read from ballooned pages will generate 100%
load in dom0 because Xen asks qemu-dm for the page content. Since the
reads come in as 8byte requests each ballooned page is tried 512
times.
Add a new hvmop HVMOP_get_mem_type to return the hvmmem_type_t for the
given pfn. Pages which are neither ram or mmio will be HVMMEM_mmio_dm.
This interface enables the crash kernel to skip ballooned pages.
Signed-off-by: Olaf Hering <olaf@aepfle.de>
Acked-by: Tim Deegan <Tim.Deegan@citrix.com>
Committed-by: Tim Deegan <Tim.Deegan@citrix.com>
xen-unstable changeset: 23298:26413986e6e0
xen-unstable date: Wed May 04 13:37:58 2011 +0100
-rw-r--r-- | xen/arch/ia64/vmx/vmx_hypercall.c | 1 | ||||
-rw-r--r-- | xen/arch/x86/hvm/hvm.c | 31 | ||||
-rw-r--r-- | xen/include/public/hvm/hvm_op.h | 25 |
3 files changed, 52 insertions, 5 deletions
diff --git a/xen/arch/ia64/vmx/vmx_hypercall.c b/xen/arch/ia64/vmx/vmx_hypercall.c index 94e0850547..2fde2f36eb 100644 --- a/xen/arch/ia64/vmx/vmx_hypercall.c +++ b/xen/arch/ia64/vmx/vmx_hypercall.c @@ -217,6 +217,7 @@ do_hvm_op(unsigned long op, XEN_GUEST_HANDLE(void) arg) break; } + case HVMOP_get_mem_type: case HVMOP_set_mem_type: case HVMOP_set_mem_access: case HVMOP_get_mem_access: diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c index 82aecbcc6c..ce3caa4fcb 100644 --- a/xen/arch/x86/hvm/hvm.c +++ b/xen/arch/x86/hvm/hvm.c @@ -3432,6 +3432,37 @@ long do_hvm_op(unsigned long op, XEN_GUEST_HANDLE(void) arg) break; } + case HVMOP_get_mem_type: + { + struct xen_hvm_get_mem_type a; + struct domain *d; + p2m_type_t t; + + if ( copy_from_guest(&a, arg, 1) ) + return -EFAULT; + + rc = rcu_lock_target_domain_by_id(a.domid, &d); + if ( rc != 0 ) + return rc; + + rc = -EINVAL; + if ( is_hvm_domain(d) ) + { + gfn_to_mfn_unshare(p2m_get_hostp2m(d), a.pfn, &t, 0); + if ( p2m_is_mmio(t) ) + a.mem_type = HVMMEM_mmio_dm; + else if ( p2m_is_readonly(t) ) + a.mem_type = HVMMEM_ram_ro; + else if ( p2m_is_ram(t) ) + a.mem_type = HVMMEM_ram_rw; + else + a.mem_type = HVMMEM_mmio_dm; + rc = copy_to_guest(arg, &a, 1) ? -EFAULT : 0; + } + rcu_unlock_domain(d); + break; + } + case HVMOP_set_mem_type: { struct xen_hvm_set_mem_type a; diff --git a/xen/include/public/hvm/hvm_op.h b/xen/include/public/hvm/hvm_op.h index d0849247a3..2a597da7d6 100644 --- a/xen/include/public/hvm/hvm_op.h +++ b/xen/include/public/hvm/hvm_op.h @@ -76,6 +76,12 @@ DEFINE_XEN_GUEST_HANDLE(xen_hvm_set_pci_link_route_t); /* Flushes all VCPU TLBs: @arg must be NULL. */ #define HVMOP_flush_tlbs 5 +typedef enum { + HVMMEM_ram_rw, /* Normal read/write guest RAM */ + HVMMEM_ram_ro, /* Read-only; writes are discarded */ + HVMMEM_mmio_dm, /* Reads and write go to the device model */ +} hvmmem_type_t; + /* Following tools-only interfaces may change in future. */ #if defined(__XEN__) || defined(__XEN_TOOLS__) @@ -109,11 +115,6 @@ typedef struct xen_hvm_modified_memory xen_hvm_modified_memory_t; DEFINE_XEN_GUEST_HANDLE(xen_hvm_modified_memory_t); #define HVMOP_set_mem_type 8 -typedef enum { - HVMMEM_ram_rw, /* Normal read/write guest RAM */ - HVMMEM_ram_ro, /* Read-only; writes are discarded */ - HVMMEM_mmio_dm, /* Reads and write go to the device model */ -} hvmmem_type_t; /* Notify that a region of memory is to be treated in a specific way. */ struct xen_hvm_set_mem_type { /* Domain to be updated. */ @@ -225,4 +226,18 @@ DEFINE_XEN_GUEST_HANDLE(xen_hvm_inject_trap_t); #endif /* defined(__XEN__) || defined(__XEN_TOOLS__) */ +#define HVMOP_get_mem_type 15 +/* Return hvmmem_type_t for the specified pfn. */ +struct xen_hvm_get_mem_type { + /* Domain to be queried. */ + domid_t domid; + /* OUT variable. */ + uint16_t mem_type; + uint16_t pad[2]; /* align next field on 8-byte boundary */ + /* IN variable. */ + uint64_t pfn; +}; +typedef struct xen_hvm_get_mem_type xen_hvm_get_mem_type_t; +DEFINE_XEN_GUEST_HANDLE(xen_hvm_get_mem_type_t); + #endif /* __XEN_PUBLIC_HVM_HVM_OP_H__ */ |