Re: [PATCH 2/7] x86/apic: Add an SVSM APIC driver

[Melody Wang]

Hi Tom,

On 8/21/26 7:40 AM, Tom Lendacky wrote:

> If that is the case, then the fix would be to move the setting of the CAA
> into the svsm_perform_call_protocol() function and just make that function
> external, which will eliminate the need for svsm_do_call().
>
> You would be a pre-patch then for fixing all the callers of
> svsm_perform_call_protocol().

This is the code, do you think this is what is in your mind?

diff --git a/arch/x86/coco/sev/svsm.c b/arch/x86/coco/sev/svsm.c
index e2d3bc3c26eb..f036a85a043b 100644
--- a/arch/x86/coco/sev/svsm.c
+++ b/arch/x86/coco/sev/svsm.c
@@ -74,6 +74,9 @@ int svsm_perform_call_protocol(struct svsm_call *call)

        flags = native_local_irq_save();

+       if (!call->caa)
+               call->caa = svsm_get_caa();
+
        ghcb = __sev_get_ghcb(&state);

        do {
@@ -87,6 +90,7 @@ int svsm_perform_call_protocol(struct svsm_call *call)

        return ret;
 }
+EXPORT_SYMBOL_GPL(svsm_perform_call_protocol);

 static u64 svsm_build_ca_from_pfn_range(u64 pfn, u64 pfn_end, bool action,
                                        struct svsm_pvalidate_call *pc)
@@ -321,7 +325,6 @@ int snp_svsm_vtpm_send_command(u8 *buffer)
 {
        struct svsm_call call = {};

-       call.caa = svsm_get_caa();
        call.rax = SVSM_VTPM_CALL(SVSM_VTPM_CMD);
        call.rcx = __pa(buffer);

@@ -345,7 +348,6 @@ bool snp_svsm_vtpm_probe(void)
        if (!snp_vmpl)
                return false;

-       call.caa = svsm_get_caa();
        call.rax = SVSM_VTPM_CALL(SVSM_VTPM_QUERY);

        if (svsm_perform_call_protocol(&call))
@@ -354,9 +356,3 @@ bool snp_svsm_vtpm_probe(void)
        /* Check platform commands contains TPM_SEND_COMMAND - platform 
command 8 */
        return call.rcx_out & BIT_ULL(8);
 }
-
-int svsm_do_call(struct svsm_call *call)
-{
-       call->caa = svsm_get_caa();
-       return svsm_perform_call_protocol(call);
-}
diff --git a/arch/x86/include/asm/sev.h b/arch/x86/include/asm/sev.h
index f958f78e1db8..9013b392ad40 100644
--- a/arch/x86/include/asm/sev.h
+++ b/arch/x86/include/asm/sev.h
@@ -526,7 +526,6 @@ u64 sev_get_status(void);
 void sev_show_status(void);
 int prepare_pte_enc(struct pte_enc_desc *d);
 void set_pte_enc_mask(pte_t *kpte, unsigned long pfn, pgprot_t new_prot);
-int svsm_do_call(struct svsm_call *call);
 void snp_kexec_finish(void);
 void snp_kexec_begin(void);

@@ -536,7 +535,7 @@ void snp_msg_free(struct snp_msg_desc *mdesc);
 int snp_send_guest_request(struct snp_msg_desc *mdesc, struct 
snp_guest_req *req);

 int snp_svsm_vtpm_send_command(u8 *buffer);
-
+int svsm_perform_call_protocol(struct svsm_call *call);
 void __init snp_secure_tsc_prepare(void);
 void __init snp_secure_tsc_init(void);
 enum es_result savic_register_gpa(u64 gpa);
@@ -619,7 +618,6 @@ static inline int rmpadjust(unsigned long vaddr, 
bool rmp_psize, unsigned long a
 static inline void setup_ghcb(void) { }
 static inline void __init
 early_snp_set_memory_private(unsigned long vaddr, unsigned long paddr, 
unsigned long npages) { }
-static inline int svsm_do_call(struct svsm_call *call) { return 0; }
 static inline void __init
 early_snp_set_memory_shared(unsigned long vaddr, unsigned long paddr, 
unsigned long npages) { }
 static inline void snp_set_memory_shared(unsigned long vaddr, unsigned 
long npages) { }
@@ -645,6 +643,7 @@ static inline void snp_msg_free(struct snp_msg_desc 
*mdesc) { }
 static inline int snp_send_guest_request(struct snp_msg_desc *mdesc,
                                         struct snp_guest_req *req) { 
return -ENODEV; }
 static inline int snp_svsm_vtpm_send_command(u8 *buffer) { return 
-ENODEV; }
+static inline int svsm_perform_call_protocol(struct svsm_call *call) { 
return -ENODEV; }
 static inline void __init snp_secure_tsc_prepare(void) { }
 static inline void __init snp_secure_tsc_init(void) { }
 static inline void sev_evict_cache(void *va, int npages) {}

Thanks,
Melody

> Thanks,
> Tom
>
> >

--
Thanks,
Melody