WORK DISTRIBUTION

AISHWARYA RAVI:

    # IMPLEMENTATION #
    
       * Configured a Linux machine in VMWare WorkStation.(Collaborated with each other)
       * Downloaded the Ubuntu disc image and installed in the VMWare WorkStation.(Collaborated with each other)
       * Built the Linux kernel source code.(Collaborated with each other)
       * Created a new kernel module with the assignment functionality.
       * Verified the output in the system message log.(Collaborated with each other)


    # ISSUES RESOLVED #:
    Resolved certificate and certificate related revocation errors faced during the execution of ** make -j <cpu num> ** command and fixed it by changing the values of following config keys (CONFIG_SYSTEM_TRUSTED_KEYS, CONFIG_SYSTEM_REVOCATION_KEYS) to empty string and disabled the config key CONFIG_DEBUG_INFO BIT for debugging related issues.

SHRUTHI SRINIVASAN:

    # IMPLEMENTATION # 
    
       * Configured a Linux machine in VMWare WorkStation.(Collaborated with each other)
       * Downnladed the Ubuntu disc image and installed in the VMWare WorkStation.(Collaborated with each other)
       * Built the Linux kernel source code.(Collaborated with each other)
       * Loaded the new module
       * Verified the output in the system message log.(Collaborated with each other)
       
    # ISSUES RESOLVED #
     Resolved library related issues while executing make oldconfig command by installing packages for flex and bison.Also resolved issues while executing make prepare command.The execution was failing as libelf-dev and libncurses-dev were not configured in the ubuntu system.

STEPS FOLLOWED TO COMPLETE THE ASSIGNMENT

• Download and install VMWare WorkStation 16

• Download Ubuntu 20.04.3 disc image.

• Configure Ubuntu in VMware Workstation.

• Allocate the resources as follows -

  • Memory - 8GB
  • Disk Space - 100GB
  • CPU - 8

• Fork the Linux repository on github account

• Clone the repository

• Create cmpe283-1.c using touch cmpe283-1.c command

• Modify the content as per as the requirement.

• cd Linux

• sudo apt-get install manpages-dev

• Copied the config file using cp /boot/config-5.11.0-38-generic .config

• Execute the following commands

  • make oldconfig
  • make prepare
  • make clean
  • make prepare
  • make -j 8 module
  • make -j 8
  • sudo make INSTALL_MOD_STRIP=1 modules_install
  • sudo make install
  • uname -a
  • sudo reboot
  • uname -a
  • make
  • sudo insmod cmpe283-1.ko
  • lsmod | grep cmpe283
  • Demsg

Issues faced during the execution

* Got an error while executing make oldconfig - Installed flex and bison libraries to resolve it
* Got an error while executing make prepare - Installed  libelf-dev  and libncurses-dev to resolve all the package related issues.
* Got an error while executing make -j <cpu num> - Changed the value of CONFIG_SYSTEM_TRUSTED_KEYS  and CONFIG_SYSTEM_REVOCATION_KEYS to empty string.
* Got an error while executing make -j <cpu num> -   Disabled  CONFIG_DEBUG_INFO BIT

Output

ASSIGNEMENT 2

WORK DISTRIBUTION

AISHWARYA RAVI

• Created leaf node %eax= 0x4FFFFFFF for case I
• Changed cpuid.c and vmx.c to implement the functionality as mentioned in the assignment 2
• Installed cpuid Pakage on inner VM
• Tested and Verified results
• Worked on the documentation.(Colloborated with Shruthi Srinivasan)

SHRUTHI SRINIVASAN

• Created leaf node %eax= 0x4FFFFFFD for case III
• Changed cpuid.c and vmx.c to implement the functionality as mentioned in the assignment 2
• Tested and verified results
• Worked on the documentation.(Collaborated with Aishwarya Ravi)

PRE REQUISITES

Assignment 1 configuration is to be set up.

STEPS FOLLOWED TO COMPLETE THE ASSIGNMENT

STEP 1

• Add code to KVM at file /linux/arch/x86/kvm/vmx/vmx.c and /linux/arch/x86/kvm/cpuid.c

• For CPUID leaf node %eax= 0x4FFFFFFF:

  • Return the total number of exits (all types) in %eax.

• For CPUID leaf node %eax= 0x4FFFFFFD:

  • Return the number of exits for the exit number provided (on input) in %ecx. The output should be returned in %eax.

WORKING CODE TO TEST THE FUNCTIONALITY

Modified cpuid.c

Modified vmx.c

STEP 2

Build the code * sudo make modules * sudo make modules_install * sudo make install * Reboot

STEP 3

• Install Virtual Manager by using the following command: sudo apt-get install virt-manager
• Open virt-manager and start virtual machine. Install CPUID package inside the inner vm.
  • sudo apt-get install cupid

STEP 4

Execute the following code for case 1: * cpuid -l 0x4FFFFFFF

* Execute dmesg command in the host system’s terminal

 ![image] (https://github.com/aishwaryaravi19/linux/blob/master/output-assignment2/Picture2.png)



* Total Exit count after rebooting
  ![image] (https://github.com/aishwaryaravi19/linux/blob/master/output-assignment2/Picture3.png)
 Total exits taken for VM reboot: 677887

STEP 5

Execute the following code for case 3: * cpuid -l 0x4FFFFFFD s -12 (Exit 12)

* Execute dmesg command in the host system’s terminal to count the exits available

* Cpuid - I 0X4fffffffd -444 - output for invalid exit code 

* cpuid - I 0x4fffffffd s-3 - output for valid exit but not defined by KVM

Questions

3. Comment of the frequency of exits Answer: Frequency of the exits depends on the system use.The number of exit increases as more priveleged operations are performed.

4.Of the exit types defined in the SDM, which are the most frequent? Least?

Answer: Most frequent exit - MSR_WRITE(count -605825) Least frequent exit - DR_ACCESS(count-8)

ASSIGNMENT 3

WORK DISTRIBUTION

AISHWARYA RAVI

• Created leaf node %eax=0x4FFFFFFE - Case 2
• Modifed cpuid.c and vmx.c as per as required
• Tested and verified the results
• Documented the steps and results

SHRUTHI SRINIVASAN

• Created leaf node %eax=0x4FFFFFFC - Case 4
• Modifed cpuid.c and vmx.c as per as required
• Tested and verified the results
• Documented the steps and results

PREREQUISITES

Assignment 1 configurations needs to be set up.

STEP 1:

Modify vmx.c and cpuid.c as per as the requirement.

• For CPUID leaf node %eax= 0x4FFFFFFE:

  • Return the higher 32 bits of the total time taken to process all exits in %ebx
  • Return the lower 32 bits of the total time taken to process all exits in %ecx
  • The values returned by %ebx and %ecx is measured across all VCPUs in every processor cycle.

• For CPUID leaf node %eax= 0x4FFFFFFC:

• Return the time taken to process the exit number provided (on input) in %ecx.

• Return the higher 32 bits of the total time taken to process all exits in %ebx

• Return the lower 32 bits of the total time taken to process all exits in %ecx

STEP 2

Build the code * sudo make modules * sudo make modules_install * sudo make install * Reboot

STEP 3

• Open virt-manager and start virtual machine. Install CPUID package inside the inner vm.
  • sudo apt-get install cupid

STEP4

  ### Case 2
   *	cpuid -l 0x4FFFFFFE

   *	Execute dmesg command in the host system’s terminal

   Total Exit count after rebooting 

   Total exits taken for VM reboot: 1486132839

STEP 5

   ### Case 4

     *	cpuid -l 0x4FFFFFFC s -32

     *	Execute dmesg command to view all the exits available count.

* Cupid -l 0x4FFFFFFC s -444 to test the output for invalid exit code.

     * cupid -l 0x4FFFFFFC s -3 to test the output for valid exit but not implemented by KVM.

Question 3

 * Comment of the frequency axis
   Frequency of the time spent depends on the type of exit.The number of exits tends to increase if more proveleged operations are performed by the system

  * Which are the most frequent and less frequent exit types?
    Most frquent - MSR_WRITE -Cycle count 4859559731
    Less frequent - DR_ACCESS - Cycle count 7625