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Date:   Fri, 19 May 2023 11:31:52 -0500
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Subject: Re: [PATCH 1/6] x86/sev: Fix calculation of end address based on
 number of pages
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From:   Tom Lendacky <thomas.lendacky@amd.com>
To:     linux-kernel@vger.kernel.org, x86@kernel.org
Cc:     Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
        Dave Hansen <dave.hansen@linux.intel.com>,
        "Kirill A. Shutemov" <kirill@shutemov.name>,
        "H. Peter Anvin" <hpa@zytor.com>,
        Michael Roth <michael.roth@amd.com>,
        Joerg Roedel <jroedel@suse.de>,
        Dionna Glaze <dionnaglaze@google.com>,
        Andy Lutomirski <luto@kernel.org>,
        Peter Zijlstra <peterz@infradead.org>
References: <20230518231434.26080-1-kirill.shutemov@linux.intel.com>
 <b5671e1d6d7b1b9e6ed9f5bde15cdd06aca2671b.1684513457.git.thomas.lendacky@amd.com>
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Hit send by mistake so I missed adding the cover letter and version 
update. Resending...

Thanks,
Tom

On 5/19/23 11:24, Tom Lendacky wrote:
> When calculating an end address based on an unsigned int number of pages,
> any value greater than or equal to 0x100000 that is shift PAGE_SHIFT bits
> results in a 0 value, resulting in an invalid end address. Change the
> number of pages variable in various routines from an unsigned int to an
> unsigned long to calculate the end address correctly.
> 
> Fixes: 5e5ccff60a29 ("x86/sev: Add helper for validating pages in early enc attribute changes")
> Fixes: dc3f3d2474b8 ("x86/mm: Validate memory when changing the C-bit")
> Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
> ---
>   arch/x86/include/asm/sev.h | 16 ++++++++--------
>   arch/x86/kernel/sev.c      | 14 +++++++-------
>   2 files changed, 15 insertions(+), 15 deletions(-)
> 
> diff --git a/arch/x86/include/asm/sev.h b/arch/x86/include/asm/sev.h
> index 13dc2a9d23c1..7ca5c9ec8b52 100644
> --- a/arch/x86/include/asm/sev.h
> +++ b/arch/x86/include/asm/sev.h
> @@ -192,12 +192,12 @@ struct snp_guest_request_ioctl;
>   
>   void setup_ghcb(void);
>   void __init early_snp_set_memory_private(unsigned long vaddr, unsigned long paddr,
> -					 unsigned int npages);
> +					 unsigned long npages);
>   void __init early_snp_set_memory_shared(unsigned long vaddr, unsigned long paddr,
> -					unsigned int npages);
> +					unsigned long npages);
>   void __init snp_prep_memory(unsigned long paddr, unsigned int sz, enum psc_op op);
> -void snp_set_memory_shared(unsigned long vaddr, unsigned int npages);
> -void snp_set_memory_private(unsigned long vaddr, unsigned int npages);
> +void snp_set_memory_shared(unsigned long vaddr, unsigned long npages);
> +void snp_set_memory_private(unsigned long vaddr, unsigned long npages);
>   void snp_set_wakeup_secondary_cpu(void);
>   bool snp_init(struct boot_params *bp);
>   void __init __noreturn snp_abort(void);
> @@ -212,12 +212,12 @@ static inline int pvalidate(unsigned long vaddr, bool rmp_psize, bool validate)
>   static inline int rmpadjust(unsigned long vaddr, bool rmp_psize, unsigned long attrs) { return 0; }
>   static inline void setup_ghcb(void) { }
>   static inline void __init
> -early_snp_set_memory_private(unsigned long vaddr, unsigned long paddr, unsigned int npages) { }
> +early_snp_set_memory_private(unsigned long vaddr, unsigned long paddr, unsigned long npages) { }
>   static inline void __init
> -early_snp_set_memory_shared(unsigned long vaddr, unsigned long paddr, unsigned int npages) { }
> +early_snp_set_memory_shared(unsigned long vaddr, unsigned long paddr, unsigned long npages) { }
>   static inline void __init snp_prep_memory(unsigned long paddr, unsigned int sz, enum psc_op op) { }
> -static inline void snp_set_memory_shared(unsigned long vaddr, unsigned int npages) { }
> -static inline void snp_set_memory_private(unsigned long vaddr, unsigned int npages) { }
> +static inline void snp_set_memory_shared(unsigned long vaddr, unsigned long npages) { }
> +static inline void snp_set_memory_private(unsigned long vaddr, unsigned long npages) { }
>   static inline void snp_set_wakeup_secondary_cpu(void) { }
>   static inline bool snp_init(struct boot_params *bp) { return false; }
>   static inline void snp_abort(void) { }
> diff --git a/arch/x86/kernel/sev.c b/arch/x86/kernel/sev.c
> index b031244d6d2d..108bbae59c35 100644
> --- a/arch/x86/kernel/sev.c
> +++ b/arch/x86/kernel/sev.c
> @@ -645,7 +645,7 @@ static u64 __init get_jump_table_addr(void)
>   	return ret;
>   }
>   
> -static void pvalidate_pages(unsigned long vaddr, unsigned int npages, bool validate)
> +static void pvalidate_pages(unsigned long vaddr, unsigned long npages, bool validate)
>   {
>   	unsigned long vaddr_end;
>   	int rc;
> @@ -662,7 +662,7 @@ static void pvalidate_pages(unsigned long vaddr, unsigned int npages, bool valid
>   	}
>   }
>   
> -static void __init early_set_pages_state(unsigned long paddr, unsigned int npages, enum psc_op op)
> +static void __init early_set_pages_state(unsigned long paddr, unsigned long npages, enum psc_op op)
>   {
>   	unsigned long paddr_end;
>   	u64 val;
> @@ -701,7 +701,7 @@ static void __init early_set_pages_state(unsigned long paddr, unsigned int npage
>   }
>   
>   void __init early_snp_set_memory_private(unsigned long vaddr, unsigned long paddr,
> -					 unsigned int npages)
> +					 unsigned long npages)
>   {
>   	/*
>   	 * This can be invoked in early boot while running identity mapped, so
> @@ -723,7 +723,7 @@ void __init early_snp_set_memory_private(unsigned long vaddr, unsigned long padd
>   }
>   
>   void __init early_snp_set_memory_shared(unsigned long vaddr, unsigned long paddr,
> -					unsigned int npages)
> +					unsigned long npages)
>   {
>   	/*
>   	 * This can be invoked in early boot while running identity mapped, so
> @@ -879,7 +879,7 @@ static void __set_pages_state(struct snp_psc_desc *data, unsigned long vaddr,
>   		sev_es_terminate(SEV_TERM_SET_LINUX, GHCB_TERM_PSC);
>   }
>   
> -static void set_pages_state(unsigned long vaddr, unsigned int npages, int op)
> +static void set_pages_state(unsigned long vaddr, unsigned long npages, int op)
>   {
>   	unsigned long vaddr_end, next_vaddr;
>   	struct snp_psc_desc *desc;
> @@ -904,7 +904,7 @@ static void set_pages_state(unsigned long vaddr, unsigned int npages, int op)
>   	kfree(desc);
>   }
>   
> -void snp_set_memory_shared(unsigned long vaddr, unsigned int npages)
> +void snp_set_memory_shared(unsigned long vaddr, unsigned long npages)
>   {
>   	if (!cc_platform_has(CC_ATTR_GUEST_SEV_SNP))
>   		return;
> @@ -914,7 +914,7 @@ void snp_set_memory_shared(unsigned long vaddr, unsigned int npages)
>   	set_pages_state(vaddr, npages, SNP_PAGE_STATE_SHARED);
>   }
>   
> -void snp_set_memory_private(unsigned long vaddr, unsigned int npages)
> +void snp_set_memory_private(unsigned long vaddr, unsigned long npages)
>   {
>   	if (!cc_platform_has(CC_ATTR_GUEST_SEV_SNP))
>   		return;