diff mbox series

[v2,06/10] i386/pc_sysfw: Ensure sysfw flash configuration does not conflict with IGVM

Message ID 613c3dc97a29fa9b8baa8acf45cefe4fac24ea87.1712141833.git.roy.hopkins@suse.com
State New
Headers show
Series [v2,01/10] meson: Add optional dependency on IGVM library | expand

Commit Message

Roy Hopkins April 3, 2024, 11:11 a.m. UTC
When using an IGVM file the configuration of the system firmware is
defined by IGVM directives contained in the file. In this case the user
should not configure any pflash devices.

This commit skips initialization of the ROM mode when pflash0 is not set
then checks to ensure no pflash devices have been configured when using
IGVM, exiting with an error message if this is not the case.

Signed-off-by: Roy Hopkins <roy.hopkins@suse.com>
---
 hw/i386/pc_sysfw.c | 23 +++++++++++++++++++++--
 1 file changed, 21 insertions(+), 2 deletions(-)

Comments

Ani Sinha April 4, 2024, 12:36 p.m. UTC | #1
> On 3 Apr 2024, at 16:41, Roy Hopkins <roy.hopkins@suse.com> wrote:
> 
> When using an IGVM file the configuration of the system firmware is
> defined by IGVM directives contained in the file. In this case the user
> should not configure any pflash devices.
> 
> This commit skips initialization of the ROM mode when pflash0 is not set
> then checks to ensure no pflash devices have been configured when using
> IGVM, exiting with an error message if this is not the case.
> 
> Signed-off-by: Roy Hopkins <roy.hopkins@suse.com>
> ---
> hw/i386/pc_sysfw.c | 23 +++++++++++++++++++++--
> 1 file changed, 21 insertions(+), 2 deletions(-)
> 
> diff --git a/hw/i386/pc_sysfw.c b/hw/i386/pc_sysfw.c
> index 3efabbbab2..2412f26225 100644
> --- a/hw/i386/pc_sysfw.c
> +++ b/hw/i386/pc_sysfw.c
> @@ -226,8 +226,13 @@ void pc_system_firmware_init(PCMachineState *pcms,
>     }
> 
>     if (!pflash_blk[0]) {
> -        /* Machine property pflash0 not set, use ROM mode */
> -        x86_bios_rom_init(MACHINE(pcms), "bios.bin", rom_memory, false);
> +        /*
> +         * Machine property pflash0 not set, use ROM mode unless using IGVM,
> +         * in which case the firmware must be provided by the IGVM file.

What if the igvm file does not contain a firmware? Can we have a check for that case somewhere and assert if firmware is absent?

> +         */
> +        if (!cgs_is_igvm(MACHINE(pcms)->cgs)) {
> +            x86_bios_rom_init(MACHINE(pcms), "bios.bin", rom_memory, false);
> +        }
>     } else {
>         if (kvm_enabled() && !kvm_readonly_mem_enabled()) {
>             /*
> @@ -243,6 +248,20 @@ void pc_system_firmware_init(PCMachineState *pcms,
>     }
> 
>     pc_system_flash_cleanup_unused(pcms);
> +
> +    /*
> +     * The user should not have specified any pflash devices when using IGVM
> +     * to configure the guest.
> +     */
> +    if (cgs_is_igvm(MACHINE(pcms)->cgs)) {
> +        for (i = 0; i < ARRAY_SIZE(pcms->flash); i++) {
> +            if (pcms->flash[i]) {
> +                error_report("pflash devices cannot be configured when "
> +                             "using IGVM");
> +                exit(1);
> +            }
> +        }
> +    }

I have not tested this change but looking at pc_system_flash_create() creates flash[0] and flash[1] for all cases (well except for isapc machines). So for igvm case, would this not cause an exit all the time?

> }
> 
> void x86_firmware_configure(void *ptr, int size)
> -- 
> 2.43.0
>
diff mbox series

Patch

diff --git a/hw/i386/pc_sysfw.c b/hw/i386/pc_sysfw.c
index 3efabbbab2..2412f26225 100644
--- a/hw/i386/pc_sysfw.c
+++ b/hw/i386/pc_sysfw.c
@@ -226,8 +226,13 @@  void pc_system_firmware_init(PCMachineState *pcms,
     }
 
     if (!pflash_blk[0]) {
-        /* Machine property pflash0 not set, use ROM mode */
-        x86_bios_rom_init(MACHINE(pcms), "bios.bin", rom_memory, false);
+        /*
+         * Machine property pflash0 not set, use ROM mode unless using IGVM,
+         * in which case the firmware must be provided by the IGVM file.
+         */
+        if (!cgs_is_igvm(MACHINE(pcms)->cgs)) {
+            x86_bios_rom_init(MACHINE(pcms), "bios.bin", rom_memory, false);
+        }
     } else {
         if (kvm_enabled() && !kvm_readonly_mem_enabled()) {
             /*
@@ -243,6 +248,20 @@  void pc_system_firmware_init(PCMachineState *pcms,
     }
 
     pc_system_flash_cleanup_unused(pcms);
+
+    /*
+     * The user should not have specified any pflash devices when using IGVM
+     * to configure the guest.
+     */
+    if (cgs_is_igvm(MACHINE(pcms)->cgs)) {
+        for (i = 0; i < ARRAY_SIZE(pcms->flash); i++) {
+            if (pcms->flash[i]) {
+                error_report("pflash devices cannot be configured when "
+                             "using IGVM");
+                exit(1);
+            }
+        }
+    }
 }
 
 void x86_firmware_configure(void *ptr, int size)