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Re: [Libvir] New (last ?) virtual cpu functions proposal



On Wed, Aug 02, 2006 at 11:47:14AM +0200, Philippe Berthault wrote:
> Here the new virtual cpu functions proposal.
> What do you think about it ?
> 

  looks fine to me, except for some extra '*' showing up around identifiers :-)
I would just add documentations for the parameters of the macros in the final
version but it's a detail.

  thanks !

Daniel

> 
> /**
> * *virVcpuInfo*: structure for information about a virtual CPU in a domain.
> */
> typedef enum {
>    VIR_VCPU_OFFLINE    = 0,    /* the virtual CPU is offline */
>    VIR_VCPU_RUNNING    = 1,    /* the virtual CPU is running */
>    VIR_VCPU_BLOCKED    = 2,    /* the virtual CPU is blocked on resource */
> *} virVcpuState*;
> 
> typedef struct _virVcpuInfo virVcpuInfo;
> struct _virVcpuInfo {
>    unsigned int number;        /* virtual CPU number */
>    int state;                  /* value from virVcpuState */
>    unsigned long long cpuTime; /* CPU time used, in nanoseconds */
>    int cpu;                    /* real CPU number, or -1 if offline */
> };
> typedef virVcpuInfo **virVcpuInfoPtr*;
> 
> 
> /**
> * *virDomainSetVcpus*:
> * @*domain*: pointer to domain object, or NULL for Domain0
> * @*nvcpus*: the new number of virtual CPUs for this domain
> *
> * Dynamically change the number of virtual CPUs used by the domain.
> * Note that this call may fail if the underlying virtualization hypervisor
> * does not support it or if growing the number is arbitrary limited.
> * This function requires priviledged access to the hypervisor.
> *
> * Returns 0 in case of success, -1 in case of failure.
> */
> int *virDomainSetVcpus*   (virDomainPtr domain,
>                         unsigned int nvcpus);
> 
> 
> /**
> * *virDomainPinVcpu*:
> * @*domain*: pointer to domain object, or NULL for Domain0
> * @*vcpu*: virtual CPU number
> * @*cpumap*: pointer to a bit map of real CPUs (in 8-bit bytes).
> *      Each bit set to 1 means that corresponding CPU is usable.
> *      Bytes are stored in little-endian order: CPU0-7, 8-15...
> *      In each byte, lowest CPU number is least significant bit.
> * @*maplen*: number of bytes in cpumap, from 1 up to size of CPU map in
> *      underlying virtualization system (Xen...).
> *      If maplen < size, missing bytes are set to zero.
> *      If maplen > size, failure code is returned.
> *
> * Dynamically change the real CPUs which can be allocated to a virtual CPU.
> * This function requires priviledged access to the hypervisor.
> *
> * Returns 0 in case of success, -1 in case of failure.
> */
> int *virDomainPinVcpu*    (virDomainPtr domain,
>                         unsigned int vcpu,
>                         unsigned char *cpumap,
>                         int maplen);
> 
> /* Macros for bit manipulation in cpumap */
> #define *USE_CPU*(cpumap,cpu)     (cpumap[(cpu)/8] |=  (1<<((cpu)%8)))
> #define *UNUSE_CPU*(cpumap,cpu)   (cpumap[(cpu)/8] &= ~(1<<((cpu)%8)))
> 
> 
> /**
> * *virDomainGetVcpus*:
> * @*domain*: pointer to domain object, or NULL for Domain0
> * @*info*: pointer to an array of virVcpuInfo structures
> * @*maxinfo*: number of structures in info array
> * @*cpumaps*: pointer to a bit map of real CPUs for all vcpus of this 
> domain.
> *      If cpumaps is NULL, then no cpumap information is returned by 
> the API.
> *      It's assumed there is <maxinfo> cpumap in cpumaps.
> *      The memory allocated to cpumaps must be (maxinfo * maplen) bytes.
> *      One cpumap inside cupmaps have the format described in 
> virDomainPinVcpu API.
> * @*maplen*: number of bytes in one cpumap, from 1 up to size of CPU map in
> *      underlying virtualization system (Xen...).
> *
> * Extract information about virtual CPUs of domain, store it in info array.
> *
> * Returns the number of info filled in case of success, -1 in case of 
> failure.
> */
> int *virDomainGetVcpus*   (virDomainPtr domain,
>                         virVcpuInfoPtr info,
>                         int maxinfo,
>                         unsigned char *cpumaps, /* may be NULL */
>                         int maplen);
> 
> /* Macros for bit testing in cpumaps */
> #define *CPU_USABLE*(cpumaps,maplen,vcpu,cpu) \
>    (cpumaps[((vcpu)*(maplen))+((cpu)/8)] & (1<<((cpu)%8)))
> 
> /*
> * Macro for copying the cpumap of a vcpu from cupmaps inside a 
> standalone cpumap.
> * This macro is useful in case of using virDomainPinVcpu() after 
> virDomainGetVcpus().
> * cpumap must be previously allocated.
> */
> #define *COPY_CPUMAP*(cpumaps,maplen,vcpu,cpumap) \
>    memcpy(cpumap, &(cpumaps[(vcpu)*(maplen)]), (maplen))
> 

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-- 
Daniel Veillard      | Red Hat http://redhat.com/
veillard redhat com  | libxml GNOME XML XSLT toolkit  http://xmlsoft.org/
http://veillard.com/ | Rpmfind RPM search engine http://rpmfind.net/


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