[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] [PATCH v2 08/12] x86/altp2m: alternate p2m memory events.
On 06/24/2015 09:01 AM, Lengyel, Tamas wrote: > On Mon, Jun 22, 2015 at 2:56 PM, Ed White <edmund.h.white@xxxxxxxxx> wrote: > >> Add a flag to indicate that a memory event occurred in an alternate p2m >> and a field containing the p2m index. Allow the response to switch to >> a different p2m using the same flag and field. >> >> Modify p2m_access_check() to handle alternate p2m's. >> >> Signed-off-by: Ed White <edmund.h.white@xxxxxxxxx> >> --- >> xen/arch/x86/mm/p2m.c | 20 +++++++++++++++++++- >> xen/include/asm-arm/p2m.h | 7 +++++++ >> xen/include/asm-x86/p2m.h | 4 ++++ >> xen/include/public/vm_event.h | 13 ++++++++++++- >> xen/include/xen/mem_access.h | 1 + >> 5 files changed, 43 insertions(+), 2 deletions(-) >> >> diff --git a/xen/arch/x86/mm/p2m.c b/xen/arch/x86/mm/p2m.c >> index 87b4b75..389360a 100644 >> --- a/xen/arch/x86/mm/p2m.c >> +++ b/xen/arch/x86/mm/p2m.c >> @@ -1516,6 +1516,13 @@ void p2m_mem_access_emulate_check(struct vcpu *v, >> } >> } >> >> +void p2m_mem_access_altp2m_check(struct vcpu *v, const >> vm_event_response_t *rsp) >> +{ >> + if ( (rsp->flags & MEM_ACCESS_ALTERNATE_P2M) && >> + altp2mhvm_active(v->domain) ) >> + p2m_switch_vcpu_altp2m_by_id(v, rsp->u.mem_access.altp2m_idx); >> +} >> > > The function should be renamed p2m_altp2m_check as it is not really > required to use mem_access at all to be able use altp2m. See my comment > below. > > >> + >> bool_t p2m_mem_access_check(paddr_t gpa, unsigned long gla, >> struct npfec npfec, >> vm_event_request_t **req_ptr) >> @@ -1523,7 +1530,7 @@ bool_t p2m_mem_access_check(paddr_t gpa, unsigned >> long gla, >> struct vcpu *v = current; >> unsigned long gfn = gpa >> PAGE_SHIFT; >> struct domain *d = v->domain; >> - struct p2m_domain* p2m = p2m_get_hostp2m(d); >> + struct p2m_domain *p2m = NULL; >> mfn_t mfn; >> p2m_type_t p2mt; >> p2m_access_t p2ma; >> @@ -1531,6 +1538,11 @@ bool_t p2m_mem_access_check(paddr_t gpa, unsigned >> long gla, >> int rc; >> unsigned long eip = guest_cpu_user_regs()->eip; >> >> + if ( altp2mhvm_active(d) ) >> + p2m = p2m_get_altp2m(v); >> + if ( !p2m ) >> + p2m = p2m_get_hostp2m(d); >> + >> /* First, handle rx2rw conversion automatically. >> * These calls to p2m->set_entry() must succeed: we have the gfn >> * locked and just did a successful get_entry(). */ >> @@ -1637,6 +1649,12 @@ bool_t p2m_mem_access_check(paddr_t gpa, unsigned >> long gla, >> req->vcpu_id = v->vcpu_id; >> >> p2m_vm_event_fill_regs(req); >> + >> + if ( altp2mhvm_active(v->domain) ) >> + { >> + req->flags |= MEM_ACCESS_ALTERNATE_P2M; >> + req->u.mem_access.altp2m_idx = vcpu_altp2mhvm(v).p2midx; >> + } >> } >> >> /* Pause the current VCPU */ >> diff --git a/xen/include/asm-arm/p2m.h b/xen/include/asm-arm/p2m.h >> index 63748ef..b31dd6f 100644 >> --- a/xen/include/asm-arm/p2m.h >> +++ b/xen/include/asm-arm/p2m.h >> @@ -109,6 +109,13 @@ void p2m_mem_access_emulate_check(struct vcpu *v, >> /* Not supported on ARM. */ >> } >> >> +static inline >> +void p2m_mem_access_altp2m_check(struct vcpu *v, >> + const mem_event_response_t *rsp) >> +{ >> + /* Not supported on ARM. */ >> +} >> + >> #define p2m_is_foreign(_t) ((_t) == p2m_map_foreign) >> #define p2m_is_ram(_t) ((_t) == p2m_ram_rw || (_t) == p2m_ram_ro) >> >> diff --git a/xen/include/asm-x86/p2m.h b/xen/include/asm-x86/p2m.h >> index 16fd523..d84da33 100644 >> --- a/xen/include/asm-x86/p2m.h >> +++ b/xen/include/asm-x86/p2m.h >> @@ -762,6 +762,10 @@ bool_t p2m_find_altp2m_by_eptp(struct domain *d, >> uint64_t eptp, unsigned long *i >> /* Switch alternate p2m for a single vcpu */ >> bool_t p2m_switch_vcpu_altp2m_by_id(struct vcpu *v, uint16_t idx); >> >> +/* Check to see if vcpu should be switched to a different p2m. */ >> +void p2m_mem_access_altp2m_check(struct vcpu *v, >> + const vm_event_response_t *rsp); >> + >> /* >> * p2m type to IOMMU flags >> */ >> diff --git a/xen/include/public/vm_event.h b/xen/include/public/vm_event.h >> index 577e971..b492f65 100644 >> --- a/xen/include/public/vm_event.h >> +++ b/xen/include/public/vm_event.h >> @@ -149,13 +149,24 @@ struct vm_event_regs_x86 { >> * potentially having side effects (like memory mapped or port I/O) >> disabled. >> */ >> #define MEM_ACCESS_EMULATE_NOWRITE (1 << 7) >> +/* >> + * This flag can be set in a request or a response >> + * >> + * On a request, indicates that the event occurred in the alternate p2m >> specified by >> + * the altp2m_idx request field. >> + * >> + * On a response, indicates that the VCPU should resume in the alternate >> p2m specified >> + * by the altp2m_idx response field if possible. >> + */ >> +#define MEM_ACCESS_ALTERNATE_P2M (1 << 8) >> > > This definition should be renamed VM_EVENT_FLAG_ALTERNATE_P2M and moved to > the appropriate location. It should also be checked for all events, not > just for mem_access, similar to how VM_EVENT_FLAG_VCPU_PAUSED is checked > for, as we might want to switch views in response to a variety of events. > Right now I worked around this be specifying the response to a singlestep > event as if it was a response to a mem_access one, but that's very hackish. Good points. I'll do as you suggest. Ed _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxx http://lists.xen.org/xen-devel
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