On 04.11.19 16:54, Cornelia Huck wrote:
> On Thu, 24 Oct 2019 07:40:24 -0400
> Janosch Frank <frankja@xxxxxxxxxxxxx> wrote:
>
>> From: Vasily Gorbik <gor@xxxxxxxxxxxxx>
>>
>> Introduce KVM_S390_PROTECTED_VIRTUALIZATION_HOST kbuild option for
>> protected virtual machines hosting support code.
>>
>> Add "prot_virt" command line option which controls if the kernel
>> protected VMs support is enabled at runtime.
>>
>> Extend ultravisor info definitions and expose it via uv_info struct
>> filled in during startup.
>>
>> Signed-off-by: Vasily Gorbik <gor@xxxxxxxxxxxxx>
>> ---
>> .../admin-guide/kernel-parameters.txt | 5 ++
>> arch/s390/boot/Makefile | 2 +-
>> arch/s390/boot/uv.c | 20 +++++++-
>> arch/s390/include/asm/uv.h | 46 ++++++++++++++++--
>> arch/s390/kernel/Makefile | 1 +
>> arch/s390/kernel/setup.c | 4 --
>> arch/s390/kernel/uv.c | 48 +++++++++++++++++++
>> arch/s390/kvm/Kconfig | 9 ++++
>> 8 files changed, 126 insertions(+), 9 deletions(-)
>> create mode 100644 arch/s390/kernel/uv.c
>
> (...)
>
>> diff --git a/arch/s390/boot/uv.c b/arch/s390/boot/uv.c
>> index ed007f4a6444..88cf8825d169 100644
>> --- a/arch/s390/boot/uv.c
>> +++ b/arch/s390/boot/uv.c
>> @@ -3,7 +3,12 @@
>> #include <asm/facility.h>
>> #include <asm/sections.h>
>>
>> +#ifdef CONFIG_PROTECTED_VIRTUALIZATION_GUEST
>> int __bootdata_preserved(prot_virt_guest);
>> +#endif
>> +#ifdef CONFIG_KVM_S390_PROTECTED_VIRTUALIZATION_HOST
>> +struct uv_info __bootdata_preserved(uv_info);
>> +#endif
>
> Two functions with the same name, but different signatures look really
> ugly.
>
> Also, what happens if I want to build just a single kernel image for
> both guest and host?
This is not two functions with the same name. It is 2 variable declarations with
the __bootdata_preserved helper. We expect to have all distro kernels to enable
both.
>
>>
>> void uv_query_info(void)
>> {
>> @@ -18,7 +23,20 @@ void uv_query_info(void)
>> if (uv_call(0, (uint64_t)&uvcb))
>> return;
>>
>> - if (test_bit_inv(BIT_UVC_CMD_SET_SHARED_ACCESS, (unsigned long *)uvcb.inst_calls_list) &&
>> + if (IS_ENABLED(CONFIG_KVM_S390_PROTECTED_VIRTUALIZATION_HOST)) {
>
> Do we always have everything needed for a host if uv_call() is
> successful?
The uv_call is the query call. It will provide the list of features. We check that
later on.
>
>> + memcpy(uv_info.inst_calls_list, uvcb.inst_calls_list, sizeof(uv_info.inst_calls_list));
>> + uv_info.uv_base_stor_len = uvcb.uv_base_stor_len;
>> + uv_info.guest_base_stor_len = uvcb.conf_base_phys_stor_len;
>> + uv_info.guest_virt_base_stor_len = uvcb.conf_base_virt_stor_len;
>> + uv_info.guest_virt_var_stor_len = uvcb.conf_virt_var_stor_len;
>> + uv_info.guest_cpu_stor_len = uvcb.cpu_stor_len;
>> + uv_info.max_sec_stor_addr = ALIGN(uvcb.max_guest_stor_addr, PAGE_SIZE);
>> + uv_info.max_num_sec_conf = uvcb.max_num_sec_conf;
>> + uv_info.max_guest_cpus = uvcb.max_guest_cpus;
>> + }
>> +
>> + if (IS_ENABLED(CONFIG_PROTECTED_VIRTUALIZATION_GUEST) &&
>> + test_bit_inv(BIT_UVC_CMD_SET_SHARED_ACCESS, (unsigned long *)uvcb.inst_calls_list) &&
>> test_bit_inv(BIT_UVC_CMD_REMOVE_SHARED_ACCESS, (unsigned long *)uvcb.inst_calls_list))
>
> Especially as it looks like we need to test for those two commands to
> determine whether we have support for a guest.
>
>> prot_virt_guest = 1;
>> }
>> diff --git a/arch/s390/include/asm/uv.h b/arch/s390/include/asm/uv.h
>> index ef3c00b049ab..6db1bc495e67 100644
>> --- a/arch/s390/include/asm/uv.h
>> +++ b/arch/s390/include/asm/uv.h
>> @@ -44,7 +44,19 @@ struct uv_cb_qui {
>> struct uv_cb_header header;
>> u64 reserved08;
>> u64 inst_calls_list[4];
>> - u64 reserved30[15];
>> + u64 reserved30[2];
>> + u64 uv_base_stor_len;
>> + u64 reserved48;
>> + u64 conf_base_phys_stor_len;
>> + u64 conf_base_virt_stor_len;
>> + u64 conf_virt_var_stor_len;
>> + u64 cpu_stor_len;
>> + u32 reserved68[3];
>> + u32 max_num_sec_conf;
>> + u64 max_guest_stor_addr;
>> + u8 reserved80[150-128];
>> + u16 max_guest_cpus;
>> + u64 reserved98;
>> } __packed __aligned(8);
>>
>> struct uv_cb_share {
>> @@ -69,9 +81,21 @@ static inline int uv_call(unsigned long r1, unsigned long r2)
>> return cc;
>> }
>>
>> -#ifdef CONFIG_PROTECTED_VIRTUALIZATION_GUEST
>> +struct uv_info {
>> + unsigned long inst_calls_list[4];
>> + unsigned long uv_base_stor_len;
>> + unsigned long guest_base_stor_len;
>> + unsigned long guest_virt_base_stor_len;
>> + unsigned long guest_virt_var_stor_len;
>> + unsigned long guest_cpu_stor_len;
>> + unsigned long max_sec_stor_addr;
>> + unsigned int max_num_sec_conf;
>> + unsigned short max_guest_cpus;
>> +};
>
> What is the main difference between uv_info and uv_cb_qui? The
> alignment of max_sec_stor_addr?
One is the hardware data structure for query, the other one is the Linux
internal state.
>
>> +extern struct uv_info uv_info;
>> extern int prot_virt_guest;
>>
>> +#ifdef CONFIG_PROTECTED_VIRTUALIZATION_GUEST
>> static inline int is_prot_virt_guest(void)
>> {
>> return prot_virt_guest;
>> @@ -121,11 +145,27 @@ static inline int uv_remove_shared(unsigned long addr)
>> return share(addr, UVC_CMD_REMOVE_SHARED_ACCESS);
>> }
>>
>> -void uv_query_info(void);
>> #else
>> #define is_prot_virt_guest() 0
>> static inline int uv_set_shared(unsigned long addr) { return 0; }
>> static inline int uv_remove_shared(unsigned long addr) { return 0; }
>> +#endif
>> +
>> +#ifdef CONFIG_KVM_S390_PROTECTED_VIRTUALIZATION_HOST
>> +extern int prot_virt_host;
>> +
>> +static inline int is_prot_virt_host(void)
>> +{
>> + return prot_virt_host;
>> +}
>> +#else
>> +#define is_prot_virt_host() 0
>> +#endif
>> +
>> +#if defined(CONFIG_PROTECTED_VIRTUALIZATION_GUEST) || \
>> + defined(CONFIG_KVM_S390_PROTECTED_VIRTUALIZATION_HOST)
>> +void uv_query_info(void);
>> +#else
>> static inline void uv_query_info(void) {}
>> #endif
>
> (...)
>
[...]
