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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] [PATCH v1 2/8]: PVH mmu changes
There are few code style issues on this patch, I suggest you run it
through scripts/checkpatch.pl, it should be able to catch all these
errors.
On Fri, 21 Sep 2012, Mukesh Rathor wrote:
> ---
> arch/x86/xen/mmu.c | 180
> +++++++++++++++++++++++++++++++++++++++++++++++--
> arch/x86/xen/mmu.h | 2 +
> include/xen/xen-ops.h | 12 +++-
> 3 files changed, 188 insertions(+), 6 deletions(-)
>
> diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c
> index b65a761..9b5a5ef 100644
> --- a/arch/x86/xen/mmu.c
> +++ b/arch/x86/xen/mmu.c
> @@ -73,6 +73,7 @@
> #include <xen/interface/version.h>
> #include <xen/interface/memory.h>
> #include <xen/hvc-console.h>
> +#include <xen/balloon.h>
>
> #include "multicalls.h"
> #include "mmu.h"
> @@ -330,6 +331,26 @@ static void xen_set_pte(pte_t *ptep, pte_t pteval)
> __xen_set_pte(ptep, pteval);
> }
>
> +void xen_set_clr_mmio_pvh_pte(unsigned long pfn, unsigned long mfn,
> + int nr_mfns, int add_mapping)
> +{
> + struct physdev_map_iomem iomem;
> +
> + iomem.first_gfn = pfn;
> + iomem.first_mfn = mfn;
> + iomem.nr_mfns = nr_mfns;
> + iomem.add_mapping = add_mapping;
> +
> + if (HYPERVISOR_physdev_op(PHYSDEVOP_pvh_map_iomem, &iomem))
> + BUG();
> +}
> +
> +static void xen_dom0pvh_set_pte_at(struct mm_struct *mm, unsigned long addr,
> + pte_t *ptep, pte_t pteval)
> +{
> + native_set_pte(ptep, pteval);
> +}
can't you just set set_pte_at to native_set_pte?
> static void xen_set_pte_at(struct mm_struct *mm, unsigned long addr,
> pte_t *ptep, pte_t pteval)
> {
> @@ -1197,6 +1218,10 @@ static void xen_post_allocator_init(void);
> static void __init xen_pagetable_setup_done(pgd_t *base)
> {
> xen_setup_shared_info();
> +
> + if (xen_feature(XENFEAT_auto_translated_physmap))
> + return;
> +
> xen_post_allocator_init();
> }
Can we move the if..return at the beginning of xen_post_allocator_init?
It would make it easier to understand what it is for.
Or maybe we could have xen_setup_shared_info take a pgd_t *base
parameter so that you can set pagetable_setup_done to
xen_setup_shared_info directly on pvh.
> @@ -1455,6 +1480,10 @@ static void __init xen_set_pte_init(pte_t *ptep, pte_t
> pte)
> static void pin_pagetable_pfn(unsigned cmd, unsigned long pfn)
> {
> struct mmuext_op op;
> +
> + if (xen_feature(XENFEAT_writable_page_tables))
> + return;
> +
> op.cmd = cmd;
> op.arg1.mfn = pfn_to_mfn(pfn);
> if (HYPERVISOR_mmuext_op(&op, 1, NULL, DOMID_SELF))
given the very limited set of mmu pvops that we initialize on pvh, I
cannot find who would actually call pin_pagetable_pfn on pvh.
> @@ -1652,6 +1681,10 @@ static void set_page_prot(void *addr, pgprot_t prot)
> unsigned long pfn = __pa(addr) >> PAGE_SHIFT;
> pte_t pte = pfn_pte(pfn, prot);
>
> + /* recall for PVH, page tables are native. */
> + if (xen_feature(XENFEAT_auto_translated_physmap))
> + return;
> +
> if (HYPERVISOR_update_va_mapping((unsigned long)addr, pte, 0))
> BUG();
> }
> @@ -1729,6 +1762,9 @@ static void convert_pfn_mfn(void *v)
> pte_t *pte = v;
> int i;
>
> + if (xen_feature(XENFEAT_auto_translated_physmap))
> + return;
> +
> /* All levels are converted the same way, so just treat them
> as ptes. */
> for (i = 0; i < PTRS_PER_PTE; i++)
> @@ -1745,6 +1781,7 @@ static void convert_pfn_mfn(void *v)
> * but that's enough to get __va working. We need to fill in the rest
> * of the physical mapping once some sort of allocator has been set
> * up.
> + * NOTE: for PVH, the page tables are native.
> */
> pgd_t * __init xen_setup_kernel_pagetable(pgd_t *pgd,
> unsigned long max_pfn)
> @@ -1802,9 +1839,13 @@ pgd_t * __init xen_setup_kernel_pagetable(pgd_t *pgd,
> * structure to attach it to, so make sure we just set kernel
> * pgd.
> */
> - xen_mc_batch();
> - __xen_write_cr3(true, __pa(pgd));
> - xen_mc_issue(PARAVIRT_LAZY_CPU);
> + if (xen_feature(XENFEAT_writable_page_tables)) {
> + native_write_cr3(__pa(pgd));
> + } else {
> + xen_mc_batch();
> + __xen_write_cr3(true, __pa(pgd));
> + xen_mc_issue(PARAVIRT_LAZY_CPU);
> + }
>
> memblock_reserve(__pa(xen_start_info->pt_base),
> xen_start_info->nr_pt_frames * PAGE_SIZE);
> @@ -2067,9 +2108,21 @@ static const struct pv_mmu_ops xen_mmu_ops __initconst
> = {
>
> void __init xen_init_mmu_ops(void)
> {
> + x86_init.paging.pagetable_setup_done = xen_pagetable_setup_done;
> +
> + if (xen_feature(XENFEAT_auto_translated_physmap)) {
> + pv_mmu_ops.flush_tlb_others = xen_flush_tlb_others;
> +
> + /* set_pte* for PCI devices to map iomem. */
> + if (xen_initial_domain()) {
> + pv_mmu_ops.set_pte = native_set_pte;
> + pv_mmu_ops.set_pte_at = xen_dom0pvh_set_pte_at;
> + }
> + return;
> + }
> +
> x86_init.mapping.pagetable_reserve = xen_mapping_pagetable_reserve;
> x86_init.paging.pagetable_setup_start = xen_pagetable_setup_start;
> - x86_init.paging.pagetable_setup_done = xen_pagetable_setup_done;
> pv_mmu_ops = xen_mmu_ops;
>
> memset(dummy_mapping, 0xff, PAGE_SIZE);
I wonder whether it would make sense to have a xen_pvh_init_mmu_ops,
given that they end up being so different...
> @@ -2305,6 +2358,92 @@ void __init xen_hvm_init_mmu_ops(void)
> }
> #endif
>
> +/* Map foreign gmfn, fgmfn, to local pfn, lpfn. This for the user space
> + * creating new guest on PVH dom0 and needs to map domU pages.
> + */
> +static int pvh_add_to_xen_p2m(unsigned long lpfn, unsigned long fgmfn,
> + unsigned int domid)
> +{
> + int rc;
> + struct xen_add_to_physmap xatp = { .u.foreign_domid = domid };
> +
> + xatp.gpfn = lpfn;
> + xatp.idx = fgmfn;
> + xatp.domid = DOMID_SELF;
> + xatp.space = XENMAPSPACE_gmfn_foreign;
> + rc = HYPERVISOR_memory_op(XENMEM_add_to_physmap, &xatp);
> + if (rc)
> + pr_warn("d0: Failed to map pfn to mfn rc:%d pfn:%lx mfn:%lx\n",
> + rc, lpfn, fgmfn);
> + return rc;
> +}
> +
> +int pvh_rem_xen_p2m(unsigned long spfn, int count)
> +{
> + struct xen_remove_from_physmap xrp;
> + int i, rc;
> +
> + for (i=0; i < count; i++) {
> + xrp.domid = DOMID_SELF;
> + xrp.gpfn = spfn+i;
> + rc = HYPERVISOR_memory_op(XENMEM_remove_from_physmap, &xrp);
> + if (rc) {
> + pr_warn("Failed to unmap pfn:%lx rc:%d done:%d\n",
> + spfn+i, rc, i);
> + return 1;
> + }
> + }
> + return 0;
> +}
> +EXPORT_SYMBOL_GPL(pvh_rem_xen_p2m);
> +
> +struct pvh_remap_data {
> + unsigned long fgmfn; /* foreign domain's gmfn */
> + pgprot_t prot;
> + domid_t domid;
> + struct xen_pvh_pfn_info *pvhinfop;
> +};
> +
> +static int pvh_map_pte_fn(pte_t *ptep, pgtable_t token, unsigned long addr,
> + void *data)
> +{
> + int rc;
> + struct pvh_remap_data *remapp = data;
> + struct xen_pvh_pfn_info *pvhp = remapp->pvhinfop;
> + unsigned long pfn = page_to_pfn(pvhp->pi_paga[pvhp->pi_next_todo++]);
> + pte_t pteval = pte_mkspecial(pfn_pte(pfn, remapp->prot));
> +
> + if ((rc=pvh_add_to_xen_p2m(pfn, remapp->fgmfn, remapp->domid)))
> + return rc;
> + native_set_pte(ptep, pteval);
Do we actually need the pte to be "special"?
I would think that being in the guest p2m, it is actually quite a normal
page.
> + return 0;
> +}
> +
> +/* The only caller at moment passes one gmfn at a time.
> + * PVH TBD/FIXME: expand this in future to honor batch requests.
> + */
> +static int pvh_remap_gmfn_range(struct vm_area_struct *vma,
> + unsigned long addr, unsigned long mfn, int nr,
> + pgprot_t prot, unsigned domid,
> + struct xen_pvh_pfn_info *pvhp)
> +{
> + int err;
> + struct pvh_remap_data pvhdata;
> +
> + if (nr > 1)
> + return -EINVAL;
> +
> + pvhdata.fgmfn = mfn;
> + pvhdata.prot = prot;
> + pvhdata.domid = domid;
> + pvhdata.pvhinfop = pvhp;
> + err = apply_to_page_range(vma->vm_mm, addr, nr << PAGE_SHIFT,
> + pvh_map_pte_fn, &pvhdata);
> + flush_tlb_all();
Maybe we can use one of the flush_tlb_range varieties instead of a
flush_tlb_all?
> + return err;
> +}
> +
> #define REMAP_BATCH_SIZE 16
>
> struct remap_data {
> @@ -2329,7 +2468,9 @@ static int remap_area_mfn_pte_fn(pte_t *ptep, pgtable_t
> token,
> int xen_remap_domain_mfn_range(struct vm_area_struct *vma,
> unsigned long addr,
> unsigned long mfn, int nr,
> - pgprot_t prot, unsigned domid)
> + pgprot_t prot, unsigned domid,
> + struct xen_pvh_pfn_info *pvhp)
> +
> {
> struct remap_data rmd;
> struct mmu_update mmu_update[REMAP_BATCH_SIZE];
> @@ -2342,6 +2483,12 @@ int xen_remap_domain_mfn_range(struct vm_area_struct
> *vma,
> BUG_ON(!((vma->vm_flags & (VM_PFNMAP | VM_RESERVED | VM_IO)) ==
> (VM_PFNMAP | VM_RESERVED | VM_IO)));
>
> + if (xen_feature(XENFEAT_auto_translated_physmap)) {
> + /* We need to update the local page tables and the xen HAP */
> + return pvh_remap_gmfn_range(vma, addr, mfn, nr, prot, domid,
> + pvhp);
> + }
> +
> rmd.mfn = mfn;
> rmd.prot = prot;
>
> @@ -2371,3 +2518,26 @@ out:
> return err;
> }
> EXPORT_SYMBOL_GPL(xen_remap_domain_mfn_range);
> +
> +/* Returns: Number of pages unmapped */
> +int xen_unmap_domain_mfn_range(struct vm_area_struct *vma,
> + struct xen_pvh_pfn_info *pvhp)
> +{
> + int count = 0;
> +
> + if (!pvhp || !xen_feature(XENFEAT_auto_translated_physmap))
> + return 0;
> +
> + while (pvhp->pi_next_todo--) {
> + unsigned long pfn;
> +
> + /* the mmu has already cleaned up the process mmu resources at
> + * this point (lookup_address will return NULL). */
> + pfn = page_to_pfn(pvhp->pi_paga[pvhp->pi_next_todo]);
> + pvh_rem_xen_p2m(pfn, 1);
> + count++;
> + }
> + flush_tlb_all();
> + return count;
Who is going to remove the corresponding mapping from the vma?
Also we might be able to replace the flush_tlb_all with a
flush_tlb_range.
> +EXPORT_SYMBOL_GPL(xen_unmap_domain_mfn_range);
> diff --git a/arch/x86/xen/mmu.h b/arch/x86/xen/mmu.h
> index 73809bb..6d0bb56 100644
> --- a/arch/x86/xen/mmu.h
> +++ b/arch/x86/xen/mmu.h
> @@ -23,4 +23,6 @@ unsigned long xen_read_cr2_direct(void);
>
> extern void xen_init_mmu_ops(void);
> extern void xen_hvm_init_mmu_ops(void);
> +extern void xen_set_clr_mmio_pvh_pte(unsigned long pfn, unsigned long mfn,
> + int nr_mfns, int add_mapping);
> #endif /* _XEN_MMU_H */
> diff --git a/include/xen/xen-ops.h b/include/xen/xen-ops.h
> index 6a198e4..6c5ad83 100644
> --- a/include/xen/xen-ops.h
> +++ b/include/xen/xen-ops.h
> @@ -24,9 +24,19 @@ int xen_create_contiguous_region(unsigned long vstart,
> unsigned int order,
> void xen_destroy_contiguous_region(unsigned long vstart, unsigned int order);
>
> struct vm_area_struct;
> +struct xen_pvh_pfn_info;
> int xen_remap_domain_mfn_range(struct vm_area_struct *vma,
> unsigned long addr,
> unsigned long mfn, int nr,
> - pgprot_t prot, unsigned domid);
> + pgprot_t prot, unsigned domid,
> + struct xen_pvh_pfn_info *pvhp);
> +int xen_unmap_domain_mfn_range(struct vm_area_struct *vma,
> + struct xen_pvh_pfn_info *pvhp);
> +
> +struct xen_pvh_pfn_info {
> + struct page **pi_paga; /* pfn info page array */
> + int pi_num_pgs;
> + int pi_next_todo;
> +};
>
> #endif /* INCLUDE_XEN_OPS_H */
> --
> 1.7.2.3
>
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